In the works: Mating, variation, and speciation: An interdisciplinary conversation


While using network theory and visualization techniques to map the genetic structure of species in space and time is in its infancy, reconfiguring how science grapples with the inherent complexity of evolution as an ever unfolding process using network approaches has the promise of making it easier to explore how comparable or dissimilar species are in their strategies for survival and reproduction. Looking long and hard at what other species do to survive and reproduce may also make it easier for all of us to see just how toxic our own social strategies—and the assumptions supporting them—can be.

Reconfiguring biological diversity 1. Toxic and obsolete assumptions

John Edward Terrell

This is part 1 of a two part article

IN AN INSIGHTFUL REVIEW of Nicholas Wade’s recent book A Troublesome Inheritance: Genes, Race and Human History (Wade 2014), the anthropological geneticist Charles C. Roseman concluded that current scientific arguments against biological racism are weak and scattered. These failings—my word, not Roseman’s—are far more than just scientifically troubling. “To recuperate a useful scientific critique of race,” he argues, “we need to come to grips with ways in which the political processes of racism have shaped human organisms over the last few hundred years” (Roseman 2014).

As Roseman notes, nobody seriously contests that human variation “is structured in geographic space, through time, and across many social divisions.” What is still up for grabs is how to explain this observable diversity. And as Roseman emphasizes, how we explain human variation cannot ignore the divisive and often destructive power of racism as a potent driver of human evolution. “Without incorporating the effects of racism into models of human variation today, we will not be able to have a cohesive theory of genes and race, and the scientific critique of race will continue to have no teeth.”

While Roseman’s observations focus on human biological diversity, the weaknesses and uncertainties he has highlighted about our explanations for variation within our species apply also to modern science’s grasp of biological diversity more broadly speaking. From this more inclusive point of view, racism is just a particularly invidious human form of social behavior capable of patterning our genetic diversity in time and space. If so, what about other species? How does the patterning of their mobility and social behavior shape their genetic diversity?

“Populations,” “admixture,” and conventional wisdom

Although the human brain can be coaxed into paying close attention to detail and nuance,  as a thinking machine it generally favors expediency and the utility of knowledge over precision and accuracy.  It is not altogether surprising, therefore, that even scientists often still take it for granted that biological species are naturally subdivided into separate “populations” or “subspecies” that  may occasionally—say under changing demographic or environmental conditions—meet and mix, and thereby produce more or less isolated “admixed” new hybrids (e.g., Moore 1994; Hellenthal et al. 2014). The question being overlooked or at any rate downplayed is how real and persistent are these assumed “populations” (Terrell and Stewart 1996; Kelly 2002).

This question may sound academic, but it is not trivial, as Charles Roseman has underscored. When it comes to human beings, the favored word in scholarly circles may be the word population or perhaps deme, group, or community, but for the chap on the street, the more likely choice wouldn’t be one of these formal terms, but rather the more down-to-earth word race. (I still vividly remember being scolded by a famous biological anthropologist decades ago when I was an undergraduate for using this particular “r” word. “We don’t use that word anymore,” he told me. “We use the term stock  instead.”)

What’s at stake here

It has been a foregone assumption in most genetics research for years that different species are by definition and by their biology isolated reproductively from one another, i.e., individuals in different species cannot mate and give birth to viable offspring capable of sustaining life for longer than a single generation. However, even the most committed cladist accepts that biological relationships below the level of the species are tokogenetic, not phylogenetic (Posada and Crandall 2001; Rieppel 2009).

Figure 1. “Tokogeny versus phylogeny. (a) Processes occurring among sexual species (phylogenetic processes) are hierarchical. That is, an ancestral species gives rise to two descendant species. (b) Processes occurring within sexual species (tokogenetic processes) are nonhierarchical. That is, two parentals combine their genes to give rise to the offspring. (c) The split of two species defines a phylogenetic relationship among species (thick lines) but, at the same time, relationships among individuals within the ancestral species (species 1) and within the descendant species (species 2 and 3) are tokogenetic (arrows).” Source: Posada and Crandall 2001, fig. 1.

Here, therefore, is the conundrum. Call them what you want, populations within any given species are not inherently isolated reproductively either by definition and by their biology. Hence to treat populations as natural units, they must first be defined and demonstrated to be isolated and discernible as such in some other way, or ways. Can this be done?

Here is one favored way when the species in question is ourselves. Many people believe that the language you speak is a reliable sign or marker of your true ethnicity and even your race. Is this right?

Hardly. As both fable and risqué jokes alike would have it, any sailor arriving in a strange port of call is likely to discover soon enough that you don’t really need to speak the local language to enjoy a good time while ashore as long as you have a few coins in your pocket. Yet scholars have long written about people living in what some see as the “underdeveloped” regions of the world as being subdivided into recognizable ethnolinguistic groups, language communities, and the like despite the fact that such euphemisms for the old-fashioned word race pigeonhole rather than map the realities of their lives (Terrell 2010a).

But if neither biology nor language inherently—i.e., “naturally”—isolates and thereby subdivides human beings as a species into different populations, subpopulations, demes, communities, stocks, or races, is there anything that does? And what about other species on earth?

Competition and tribalism, or isolation-by-distance?

As Roseman has remarked: “All analyses of human variation make strong assumptions about the mode, tempo, and pattern whenever they interpret statistical results to make evolutionary conclusions” (Roseman 2016). Favored explanations for or against the assumption that our species can be subdivided into enduring natural populations largely fall into one or the other of two basic sorts.

On the one hand, there has long been anecdotal and scholarly evidence, too, that geography and topography can limit how well and how often people are able to stay in touch with one another socially and intellectually as well as sexually. As the authors of one recent study commented, research has shown that there is a strong positive correlation between global genetic diversity within our species and geographic distance. The correlations observed have often been interpreted “as being consistent with a model of isolation by distance in which there are no major geographic discontinuities in the pattern of neutral genetic variation” (Hunley et al. 2009).

As these same authors note, however, discordant gene frequency patterns are also common within our species. It is obvious, too, that physical and social impediments to gene flow have regularly produced both larger discontinuities as well as concordant allele frequency patterns than would be expected based solely on isolation-by-distance (clinal) models of variation (Ibid.).

Adding social impediments to the mix of possible explanations brings into play the second way many have tried to explain why people around the globe appear to be so diverse. While there are many variants of this alternative argument, the essential ingredients are the baseline assumptions that (a) competition between individuals and groups is the main driving force of evolution, (b) human beings are by nature selfish and aggressive creatures, and (c) until recently humans lived in small tribal groups that were not just suspicious of strangers and other communities near and far, but were frequently at war them them, too. All of these claims are not only questionable, but are arguably contrary to the fundamental evolved characteristics of our species (Terrell 2015).

Part 2: Coming to grips with diversity 


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Dyer, Rodney J., and John D. Nason. 2004. Population graphs: The graph theoretic shape of genetic structure. Molecular ecology 13, 7: 1713-1727.

Fortuna, Miguel A., Rafael G. Albaladejo, Laura Fernández, Abelardo Aparicio, and Jordi Bascompte. 2009. Networks of spatial genetic variation across species. Proceedings of the National Academy of Sciences 106, 45: 19044-19049.

Friedlaender, Jonathan S., Françoise R. Friedlaender, Jason A. Hodgson, Matthew Stoltz, George Koki, Gisele Horvat, Sergey Zhadanov, Theodore G. Schurr, and D. Andrew Merriwether. 2007. Melanesian mtDNA complexityPLoS One 2, 2: e248.

Friedlaender, Jonathan S., Françoise R. Friedlaender, Floyd A. Reed, Kenneth K. Kidd, Judith R. Kidd, Geoffrey K. Chambers, Rodney A. Lea et al. 2008. The genetic structure of Pacific IslandersPLoS Genet 4, 1: e19.

Garroway, Colin J., Jeff Bowman, Denis Carr, and Paul J. Wilson. 2008. Applications of graph theory to landscape genetics. Evolutionary Applications 1, 4: 620-630.

Greenbaum, Gili, Alan R. Templeton, and Shirli Bar-David. 2016. Inference and analysis of population structure using genetic data and network theory. Genetics 202.4: 1299-1312.

Hellenthal, Garrett, George BJ Busby, Gavin Band, James F. Wilson, Cristian Capelli, Daniel Falush, and Simon Myers. 2014. A genetic atlas of human admixture history.” Science 343, 6172: 747-751.

Hunley, Keith, Michael Dunn, Eva Lindström, Ger Reesink, Angela Terrill, Meghan E. Healy, George Koki, Françoise R. Friedlaender, and Jonathan S. Friedlaender. 2008. Genetic and linguistic coevolution in Northern Island MelanesiaPLoS Genet 4, no. 10 (2008): e1000239.

Hunley, Keith L., Meghan E. Healy, and Jeffrey C. Long. 2009. The global pattern of gene identity variation reveals a history of long‐range migrations, bottlenecks, and local mate exchange: Implications for biological race. American Journal of Physical Anthropology 139, 1: 35-46.

Kelly, Kevin M.,  2002. Population. In Hart, J. P. & Terrell, J. E. (eds.) Darwin and Archaeology: A handbook of key concepts, pp 243–256. Westport, Ct: Bergin & Garvey.

Moore, John H. 1994. Putting anthropology back together again: The ethnogenetic critique of cladistic theory. American Anthropologist (1994): 925-948.

Posada, David, and Keith A. Crandall. 2001. Intraspecific gene genealogies: Trees grafting into networks. Trends in Ecology & Evolution 16, 1: 37-45.

Pritchard, Jonathan K., Matthew Stephens, and Peter Donnelly. 2000. Inference of population structure using multilocus genotype data. Genetics 155, 2: 945-959.

Rieppel, Olivier. 2009. Hennig’s enkaptic system. Cladistics 25, 3: 311-317.

Roseman, Chartes C. 2014. Troublesome Reflection: Racism as the Blind Spot in the Scientific Critique of Race” Human biology 86, 3: 233-240.

Roseman, Charles C. 2014. “Random genetic drift, natural selection, and noise in human cranial evolution. Human Biology 86, 3: 233-240.

Skoglund, Pontus, Cosimo Posth, Kendra Sirak, Matthew Spriggs, Frederique Valentin, Stuart Bedford, Geoffrey R. Clark et al. 2016. Genomic insights into the peopling of the Southwest Pacific. Nature 538: 510-513.

Terrell, John Edward. 2006. Human biogeography: Evidence of our place in nature. Journal of Biogeography 33, 12: 2088-2098.

Terrell, John Edward. 2010a. Language and material culture on the Sepik coast of Papua New Guinea: Using social network analysis to simulate, graph, identify, and analyze social and cultural boundaries between communities. Journal of Island & Coastal Archaeology 5, 1: 3-32.

Terrell, John Edward. 2010b. Social network analysis of the genetic structure of Pacific islanders. Annals of human genetics 74, 3: 211-232.

Terrell, John Edward. 2015. A Talent for Friendship: Rediscovery of a Remarkable Trait. Oxford University Press.

Terrell, John Edward, and Pamela J. Stewart. 1996. The paradox of human population genetics at the end of the twentieth century. Reviews in Anthropology 25, 1: 13-33.

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© 2017 John Edward Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.

Statistical probability vs. baseline plausibility

John Edward Terrell

WE ARE LIVING IN INTERESTING TIMES. Pundits are saying many of us in the United States are no longer able to distinguish between fact and fiction. Globally speaking and equally alarming, the world may be returning to the Dark Ages before the Renaissance when faith rather than informed skepticism ruled the day.

Figure 1. Despite evidence to the contrary, some today deny that the earth’s climate has changed radically since the start of the Industrial Revolution. Source:

Drill down below the level of popular journalism and social media chatter, and you will discover that even scientists today stand accused of undermining popular faith in facts & figures. Christie Aschwanden at FiveThirtyEight is one of many science writers reporting that scientists have apparently been using statistical tests of significance (in particular, p-values)[1] to decide how true their results may be and whether they should write up their findings for publication. Yet, as Aschwanden observes: “The p-value only tells you something about the probability of seeing your results given a particular hypothetical explanation—it cannot tell you the probability that the results are true or whether they’re due to random chance.”

Drill down yet deeper below the level of common everyday understanding and it turns out statisticians, too, are adding to our collective uncertainty about who and what to believe in. Apparently they no longer agree on how to do what they do, statistically speaking.[2] If they aren’t sure, how can mortals like ourselves decide who to believe and what’s what?

What’s to be done?

If it is true that sweet reason is on the wane in the world today, what can be done—borrowing from a recent presidential campaign—to make America think again?

A conventional response would be that we must buckle down and commit ourselves anew to paying proper attention to data—solid, down-to-earth facts & figures. Surely this isn’t such an impossible task? And to help us out, let’s not forget that modern statistical tests of significance—however contested nowadays they may be by professional statisticians—were developed by experts years ago to help us conclude whether we have enough facts on the table to decide what they are showing us. Therefore, shouldn’t combining due diligence for real facts with properly employed statistical testing be sufficient to get us past the current “post-factual” crisis?

Unfortunately such a seemingly self-evident way of confronting today’s reported decline in the quality of human wisdom and collective insight is not only too simple, but also naive. Here’s why.

The mind’s artful creativity

The biologist François Jacob—he shared Nobel Prize in Medicine in 1965 with Jacques Monod and André Lwoff—titled his 1982 book about evolution The Possible & the Actual.[3] This title seems misleading. Jacob is not advocating in the three beautifully written essays in this slim volume for a traditional no-nonsense view of science as the rock-solid quest for the actual—for truth and certainty—although in his preface he does say:

. . . human life always involves a continuous dialogue between the possible and the actual. A subtle mixture of belief, knowledge, and imagination builds before us an ever changing picture of the possible. It is on this image that we mold our desires and fears. It is to this possible that we adjust our behavior and actions. In a way, such human activities as politics, art, and science can be viewed as particular ways of conducting this dialogue between the possible and the actual, each one with its own rules.

Yet Jacob’s message for us is not as elementary as this statement may suggest. As a committed evolutionist, he has in mind a decidedly utilitarian view of this purported dialogue. In his own words:

In lower vertebrates, sensory information is converted into moto-nervous information in a rigid way. Such animals appear to live in a world of global stimuli closely linked to processes of appropriate responses, what ethnologists call “innate releasing mechanisms.” In contrast, in birds and even more so in mammals, the enormous amount of information coming from the environment is sorted out by sense organs and processed by the brain, which produces a simplified and useful representation of the external world. The brain functions, not by recording an exact image of the world taken as a metaphysical truth, but by creating its own picture.

From this perspective, therefore, asking how truthfully your brain is taking in the world around you is off the mark. The real issue is how usefully it is doing so. “The external reality, the ‘reality’ of which we all have intuitive knowledge, thus appears as a creation of the nervous system. It is, in a way, a possible world, a model allowing the organism to handle the bulk of incoming information and make it useful for its everyday life.”

The plausible and the possible 

Over the years since the publication of The Possible & the Actual, research in cognitive psychology and neuroscience has done much to clarify how—and how selectively—the human mind constructs what Jacob calls the particular “possible world” within which it dwells.[4] Seen from your nervous system’s point of view, the job we are doing when we are dealing with the world isn’t drawing the line, so to speak, between what Jacob called the possible and the actual, but rather between the plausible and the possible —between what our experiences have taught us to expect to find “out there” in the real world and what might possibly be there based instead on logic or fantasy rather than facts & figures (see fig. 2).

Figure 2. From your nervous system’s point of view, the task you are constantly facing when you are dealing with the world around you is where to draw the line between the possible and the plausible, not the possible and the actual.

If so, then as Daniel Kahneman and others have been saying for years, where we draw the line between the plausible and the possible depends not only on facts & figures bolstered perhaps by statistical analyses, but also on our previous experiences, biases, and prior assumptions about the world and how it works that may not only be all but impossible to put on the table but may not even be part of our conscious awareness.[5]


Headlines lamenting that many of us have seemingly lost the ability to distinguish fact from fiction may be catchy and provocative, but we know enough now about how the human mind constructs its sense of reality to conclude—along with Jacob, Kahneman and others—that paying proper attention to facts & figures is only part of the challenge we face nowadays. It can be argued that how science itself, for example, is conventionally done focuses too much on weighing hypotheses in the light of evidence, and not enough on where hypotheses, so to speak, come from in the first place (see fig. 3).

Figure 3. Science is not just an interplay between evidence and hypotheses, but also with the assumptions, beliefs, and prejudices that make some hypotheses seemly more worthy of study and experimentation than others.

The operative question we need to be asking these days, therefore, is not only the statistician’s old “p-value” question “Do I have enough evidence in favor of my hypothesis to reject the null hypothesis?” We must be attending also more than currently seems popular to the broader question “Why do I find my favored hypothesis plausible enough to spend time and money taking it seriously?”


[1] Nuzzo, Regina. “Statistical errors.” Nature 506, no. 7487 (2014): 150-152.

[2] Rodgers, Joseph Lee. “Moving in Parallel toward a Modern Modeling Epistemology: Bayes Factors and Frequentist Modeling Methods.” Multivariate Behavioral Research 51, no. 1 (2016): 30-34.

[3] Jacob, François. The Possible and the Actual. Pantheon, 1982.

[4] Pouget, Alexandre, Jeffrey M. Beck, Wei Ji Ma, and Peter E. Latham. “Probabilistic brains: knowns and unknowns.” Nature neuroscience 16, no. 9 (2013): 1170-1178.

[5] Kahneman, Daniel, and Shane Frederick. “A model of heuristic judgment.” The Cambridge handbook of thinking and reasoning (2005): 267-293.

Ascoli, Giorgio A., Matthew M. Botvinick, Richards J. Heuer, and Rajan Bhattacharyya. “Neurocognitive models of sense-making.” Biologically Inspired Cognitive Architectures 8 (2014): 82-89.

John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

© 2017 John Edward Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.

America’s latest “cargo cult”?

John Edward Terrell

In the 16th century, faced with reformers who thought they knew the way forward better than he did, Martin Luther is famous for having said what Jesus once said (Matthew 16:23) “Devil get thee behind me.” Waking up on Wednesday morning, November 9th, the majority of voters in America may have felt the same. Trump hadn’t won the election. Yet he had won the American presidency thanks to the peculiar institution of the Electoral College. Trump and the reformist movement of the seemingly disadvantaged and overlooked in American society he asserted he was leading would now be empowered to drain the swamp in Washington and make America great again.


Or maybe not. Since the election everyone or her brother has come forward with an explanation for what happened to bring about such a cataclysmic realignment of the stars. It’s the economy. No, it’s Neoliberalism. No, it’s racism, pure and evil. No again, it’s the sheer stupidity of the American masses. The list of reasons for the success of The Donald is as lengthy as there are people in the room to offer them.

I am an anthropologist who works in the South Pacific where social movements like Trump’s have been commonplace. Out there we call them “cargo cults” since many of these often short-lived social uprisings have centered on ways to miraculously achieve wealth and Western material goods. Academics also call them “nativistic movements.” Others prefer “millenarian movements,” and suggest Christianity began as just such reformist movement among the discontented Jewish faithful living under yoke of Roman rule. The anthropologist Anthony F. C. Wallace at the University of Pennsylvania, however, preferred instead “revitalization movements.” Whatever label used, Wallace defined such a social movement as a “deliberate, organized, conscious effort by members of a society to construct a more satisfying culture.”

Many years ago I had the good fortune to take Wallace’s course on these self-conscious populist efforts by which people seek to recover their sense of self-worth and dignity. If he were alive today—he died in 2015 at 92—my wager would be that he might have predicted the outcome of our recent election. He would have seen Trump for what he is, not the Devil incarnate. But rather a razzle-dazzle Harold Hill kind of prophet, however flawed or sincere you take him to be.

Wallace also might have observed—perhaps even in time to save the day for her—that the way to handle an upstart like Donald J. Trump  is definitely not the way Hillary tackled him. Not by ridicule or tones of elite superiority, but instead by matching his magical vision of what makes America great with an equally visionary (and perhaps similarly magical) wish-dream of her own. In short, she should have fought fire with fire much the way Bernie Sanders did for many months before the Democratic Convention. You don’t have to be Harry Potter to know it takes magic to defeat magic.

Wallace was an authority on the spiritual and social revivalist movement among the Iroquois of upstate New York in the early 19th century inspired and led by the Seneca prophet Handsome Lake. Here are a few basic facts. A century earlier, the Iroquois had been a powerful political and economic force in the northeastern United States thanks to the fur trade. Then they had the misfortune to side with the British during the American Revolution. Thereafter, they found themselves cramped into small reservations on both sides of Canada-U.S.A. border.

No need to give you details of Handsome Lake’s prophetic message or the religious movement he led until his death in 1815 beyond noting that many today still embrace his message of redemption. Here instead is the lesson for all of us Wallace drew from his scholarly research on Handsome Lake and also several hundred other similar case studies down through history.[1]

Wallace argues that revitalization movements in general, not only what Handsome Lake said he was inspired by the Creator to lead, have a common pattern that can be broken down into five steps or phases of development.[2] Wallace’s own phrasing of these five is academic. I have rewritten them to make them more user-friendly by restating them as if being seen in hindsight by someone participating in such a movement.

  1. Once upon a time life was good. We were happy, hopeful, and successful.
  2. Then things changed, and we started feeling that how we were living was not fulfilling our needs and aspirations.
  3. We entered an increasingly difficult time when our old ways no longer gave us what we want out of life. Many of us cast about for alternative and often unsatisfactory ways to bring meaning back into our lives by turning to alcohol, drugs, or social deviance. Disillusionment and apathy became common.
  4. Then suddenly someone came forward with a transformative vision, a way by which we could rediscover better days—Wallace called such an inspirational experience a prophetic “vision-dream”—setting out what must be done to feel good again, and be as successful as we once were. Here Wallace’s own words directly apply: “Converts are made by the prophet. Some undergo hysterical seizures induced by suggestion in a crowd situation; some experience an ecstatic vision in private circumstances; some are convinced by more or less rational arguments, some by considerations of expediency and opportunity. A small clique of special disciples (often including a few already influential men) clusters about the prophet and an embryonic campaign organization develops with three orders of personnel: the prophet; the disciples; and the followers. Frequently the action program from here on is effectively administered in large part by a political rather than a religious leadership. Like the prophet, many of the converts undergo a revitalizing personality transformation.”
  5. So now it looks like we are in for good times again. Perhaps. As Wallace wrote: “This group program may, however, be more or less realistic and more or less adaptive: some programs are literally suicidal; others represent well-conceived and successful projects of further social, political, or economic reform; some fail, not through any deficiency in conception and execution, but because circumstances made defeat inevitable.”

Who knows whether Donald Trump has ever had anything like a prophetic vision-dream in all his 70 years of life. However, judging by his public performances during the recent campaign, it can be maintained he did begin to see himself as the true prophet (“I am your voice”) of his very own personal revitalization movement.[3]

Is he sincere? Who knows? But here is my first point. What we are now experiencing in America isn’t something new and certainly not something strange. So stop trying to pin down and blame this or that for why The Donald won. People can be unhappy with their lot in life for countless reasons, not just because down deep inside they genuinely loathe immigrants, are racists, are fed up with the same-old, same-old coming out of Washington, or any of the other countless excuses being offered by pundits or exchanged at Starbucks between friends still in shock.

Here’s my second point. It is time to focus on Wallace’s last step. Here there is reason to worry. As Wallace wrote: “In instances where organized hostility to the movement develops, a crystallization of counter-hostility against unbelievers frequently occurs, and emphasis shifts from cultivation of the ideal to combat against the unbeliever and uncertainty.” I am not the first suggest we will be going down a very rocky road to 2020. Since I am almost as old as he is, it is fair for me to say to Bernie Sanders that we will need a new prophet to lead those of us who were in this camp to the Promised Land.

[1] Wallace, Anthony. Death and Rebirth of Seneca. Vintage, 2010.

[2] Wallace, Anthony FC. “Revitalization movements.” American anthropologist58, no. 2 (1956): 264-281.


This post was first published on 1 January 2017 at SCIENCE DIALOGUES, and a link was corrected on 11 January 2017

John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

© 2017 John Edward Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.

Network science: The language of integrative research

Please note: this commentary, recovered on 9-Jan-2017, was originally published in Science Dialogues on 16-May-2015.

Mathematics, they say, is the language of science. When it comes to what is happening—or has happened—down here on earth, it is beginning to look like the right dialect of mathematics to learn is what is now being called (somewhat confusingly) network science.

When the goal is integrating research discoveries across disciplines as diverse as archaeology, primatology, neurobiology, and geochemistry, the mathematics of networks is the Esperanto of choice.

Field Museum in Chicago is one of the world’s largest natural history and anthropology museums. Scientists working there study the world and its human inhabitants from scores of different research directions, both pure and applied. Integrating these often seemingly disparate specialities so that the results of so much scholarship can be communicated to the public through exhibits and publications has always been a problem.

Under the leadership of Thorsten Lumbsch, Ph.D., the Director of Integrative Research at the Museum, “The Field” as it is affectionately known in Chicago is pushing back against research specialization using network science. Here is one example.

A social network is a set of actors defined by their ties, links, or relationships with one another (e.g., friendship networks, ecological networks, global trade networks, and protein interaction networks) rather than by their individual characteristics (attributes) as actors. Since the research focus is on relationships rather than on characteristics, statistical methods  in network science are being developed that do not need to assume—unlike in traditional statistical analyses—that the observations being studied are independent of one another.

Dr. Termeh Shafie, who is currently a Visiting Bass Scholar at the Field,  arrived in mid April from the Algorithimics Department at the University of Konstanz in Germany to help the Field’s scientists apply the statistical methods and models of network science to their research datasets which are as seemingly dissimilar as gorilla social interactions, sharks swimming in the ocean, the genetics of lichens, and the decorations on prehistoric American potshards.

When asked about her work at the Field Museum in Chicago, Termeh Shafie explains:

"The first step will be to learn more about the empirical data at hand, the hypotheses about these data being considered, and how to embed a network approach to them. The second step will be to develop network models based on these hypotheses. This requires the mathematical formulation of models, programming these models using statistical software, and then running simulations. Goodness-of-fit tests can be used to test the fit of the models to the data. Once suitable models are identified, statistics can be used to measure different properties of the networks under study and unlock information in them using the models as predictive tools. Within a level of certainty, we can then predict trends and behavior patterns even for parts of the networks we don’t yet have data for."

On Wednesday, May 13th, Dr. John P. Hart (Director, Research & Collections Division, New York State Museum), Dr. Mark Golitko (Regenstein Research Scientist), and James Zimmer-Dauphinee (2015 Regenstein Intern) participated with Shafie in a small-group Network Science Workshop at the Museum exploring ways to apply network analysis to a large database of information about pottery designs on ancient vessels from 102 archaeological sites to help unravel how communities across southern Ontario coalesced between ca. A.D. 1350 and 1650 into the larger regional populations that ultimately became the historically documented Huron confederacy.

Left to right: John Hart, Termeh Shafie, James Zimmer-Dauphine, Mark Golitko
Left to right: John Hart, Termeh Shafie, James Zimmer-Dauphinee, Mark Golitko

Shafie will be at the Field until August 15th, but even after she returns to Germany, she will continue to be the “networks link” between scientists at the Museum and the Algorithmics Unit under the direction of Professor Ulrik Brandes in the Department of Computer & Information Science at the University of Konstanz.


Logical seduction and historical delusion

John Edward Terrell

Please note: this commentary, recovered on 9-Jan-2017, was originally published in Science Dialogues on 20-Feb-2015.

In his acclaimed novel The Oxford Murders, the Argentinean writer and mathematician Guillermo Martínez engagingly shows how easy it is to hide the truth from others by getting them to think that a series of similar events—in this instance, a series of murders—is happening because, when taken in sequence, they appear to add up to a coded message that we are being taunted to decipher.

Judging by appearances, each murder apparently symbolizes one of the logical steps in a predictable sequence, just as most of us would probably agree that the next logical number in the familiar series 2, 4, 8, and 16 must be the multiple 32.  Perhaps, but as the philosopher Ludwig Wittgenstein famously observed, any finite sequence of numbers can be continued in a variety of different ways, not just in the one way that may seem reasonable (Biletzki and Matar 2006).

For example, the narrator, whose name we are never told, is asked early in this novel if he can figure out what is the next symbol in the odd series reproduced here as Fig. 1a.

Figure 1.
Figure 1. Alternative possible solutions
to Martínez’s cryptic symbol series.

Although Martínez never shows us the solution he has in mind (the narrator merely tells us later on that the answer is the number series 1, 2, 3, 4), we suspect those who find riddles like this one appealing are likely to say the solution shown in Fig. 1b is the right resolve:  an answer derived from the rules of symmetry (Fig. 1c). Yet in keeping with Martínez’s revealing observations about both logic and magic set here and there in this story, what if the proper solution is not so playful?

For example, what if the three symbols already revealed follow instead the alternative rule that one stroke equals 1?  If this were so, then the missing fourth symbol in this cryptic series would not be an “M” with a bar drawn horizontally through it (in keeping with our different rule, this strange symbol could stand instead for the number 5), but disconcertingly could be drawn either as a single stroke (Fig. 1d), or possibly as an inscribed circle, the letter “O,” or a zero (Fig. 1e).

Doubt as to the proper resolve of Martínez’s series of symbols illustrates Wittgenstein’s cryptic and oft-quoted remark:  “This was our paradox:  no course of action could be determined by a rule, because every course of action can be made out to accord with the rule. The answer was:  if everything can be made out to accord with the rule, then it can also be made out to conflict with it. And so there would be neither accord nor conflict” (quoted in:  Biletzki and Matar 2006).

I am not a philosopher, nor a novelist.  It seems to me, however, that Martinez’s tale and Wittgenstein’s remark both tell us something about ourselves, about how we are given to looking for similarities among things and events proving that what we are seeing makes sense not by chance but necessity.  It might even be argued that human beings are strongly predisposed to equate similarity with necessity.

This is why we need statisticians, however much statistics may sometimes seem only a cultivated way of lying for effect.  They keep us from foolishly jumping to the conclusion that similarities in appearance or similarities in effect are necessarily similarities of cause.

And in this regard, we need to remember that when statisticians say that something should be attributed to “chance,” they do not mean “without cause.”  Far from it:  the point they are making is that the cause (or causes) is not necessarily the one we think it is.

Note: These observations were originally published as the introduction in my chapter "Return to the entangled bank: Deciphering the Lapita cultural series" in Sheppard, P. J., Thomas, T., and Summerhayes, G. R., eds., Lapita: Ancestors and Descendants, pages 255-269. Monograph 28. New Zealand Archaeological Association, Auckland, 2009.

Biletzki, Anat and Matar, Anat, “Ludwig Wittgenstein”, The Stanford Encyclopedia of Philosophy (Spring 2014 Edition), Edward N. Zalta (ed.), URL = <>.


John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

© 2015 John Edward Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.


Thinking about thinking 4. Our social baseline

John Edward Terrell and Gabriel Stowe Terrell

Please note: this commentary, recovered on 9-Jan-2017, was originally published in Science Dialogues on 16-April-2015.

“The first thing in a visit is to say ‘How d’ye do?’ and shake hands!” And here the two brothers gave each other a hug, and then they held out the two hands that were free, to shake hands with her.

Alice did not like shaking hands with either of them first, for fear of hurting the other one’s feelings; so, as the best way out of the difficulty, she took hold of both hands at once . . .

Through the Looking-Glass by Lewis Carroll, 1871

AT THE HANDS OF SOMEONE like William Shakespeare or Virginia Woolf, humans may come off sounding complex, cantankerous, and downright mean at times, but often and also kind, noble, loving, and at least momentarily wise and intelligent. On the other hand, portrayals of our species in the reckonings of science are often far more one-sided and two-dimensional. Thus according to the zoologist Edward O. Wilson (2012) we are a tribal eusocial  species committed to killing outsiders for the good of our home group. The evolutionary psychologist Steven Pinker (2011a) maintains that we all have in effect if not in fact violent demons lurking within us that must be tamed by reason, compassion, and good governance. The social scientists Samuel Bowles and Herbert Gintis (2011) have expressed a more favorable view of human nature, but again like Wilson and Pinker, they have described our willingness to cooperate with one another as an evolutionary mystery in need of resolution given that humans are selfish at heart and can be self-serving in their motivations.

The most parsimonious proximal explanation of cooperation, one that is supported by extensive experimental and other evidence, is that people gain pleasure from or feel morally obligated to cooperate with like-minded people. People also enjoy punishing those who exploit the cooperation of others, or feel morally obligated to do so. (Bowles and Gintis 2011: 3)
Dubious assumptions

There are two major assumptions at the ground level of most current scientific analyses of human nature. The first is that selfishness is one of the prime movers of biological evolution. The second is the claim that human cooperation is based on reason, shame, and good gamesmanship. “The most important psychological contributor to the decline of violence over the long term may instead be reason: the cognitive faculties, honed by the exchange of ideas through language, that allow us to understand the world and negotiate social arrangements” (Pinker 2011b: 310). Both of these assumptions are questionable.

Neo-Darwinian determination

The fundamentals of evolutionary thinking as a way of explaining what we are seeing in the world of today and in the past have changed over time since Darwin’s day (Amundson 2014). Tom Clark has shown in his series of commentaries at SCIENCE DIALOGUES on Darwin’s use of “use and disuse” that during the latter half of the 20th century, the neo-Darwinian assumption that genes and environments were sufficient causes of observed behavior “turned natural selection from an animate doing into a physical happening. Attributing behavior to stable causes both inside (molecules) and outside (environment) turned animals into spectators, along for the ride.”

Clark underscores that how we tell our story of what it means to be human and how we have evolved to be the sort of animal we are directly leverages or constrains how well we handle our individual and collective impacts on the earth and our fellow human beings.

As Michael Ruse (2014) has observed, today natural selection is the mechanism seen by most experts on evolution as the chief reason  for organic change. It is perplexing, however, that when it comes to our species, attempts to explain our general willingness to cooperate with one another often take it as self-evident that selfishness, infra-specific competition, and gamesmanship (Potter 1947; Rand et al. 2013) rule the day even when we seem to be acting in kind, considerate, and evidently caring ways towards others (Terrell 2015: 111–117).

Such scientific cynicism may make perfect sense given the ruling assumptions of neo-Darwinian theory today, but the picture looks quite different if it isn’t accepted from the get-go that selfishness has to be a part of every permissible Darwinian explanation for life’s diversity and history on earth.

Social baseline theory

The psychologists Lane Beckes and his colleague James Coan are studying empathy and cooperation based on a radically different view of what it means to be human, a research tactic they call social baseline theory (Beckes and Coan 2011). Their working assumption is one that many would accept with little disagreement: being a social animal gives any species a genuine and practical advantage in the Darwinian struggle for survival and reproduction. And for humans at least, having the capacity to live and work closely with others also gives us a social baseline of emotional support and security. So much so, they say, that our social ties with other people are in effect an extension of the way the human brain interacts with the world. As a consequence, when we are around others we know and trust, we can let down our guard and relax.

From this perspective, the experienced payoffs are more than emotional. When we thus feel safe and secure, we are literally able to devote less energy—and we would add, less time—to staying alert for possible threats and uncertainties. Indeed, they have argued that the human brain has evolved to assume the presence of other people. In their words: “In our view, the human brain is designed to assume that it is embedded within a relatively predictable social network characterized by familiarity, joint attention, shared goals, and interdependence.”

On the other side of the mirror

Beckes and Coan have said a major saving grace of human sociality is the energetic cost benefit of not having to be the only one looking out for number one (Beckes and Coan 2011; Coan and  Maresh 2014; Coan and Sbarra 2015). While we would grant that there may be be such a cost benefit, we are uncertain how decisive this savings has been in shaping human evolution. After all, the probability of survival is determined not only by how much effort you have to put into the struggle. It can be argued that we are such strongly social animals for other reasons, too. First, we critically depend on social learning to know how to survive in the first place. Second, many of us—but admittedly not all—are predisposed socially and emotionally to be caregivers because our offspring wouldn’t survive the first years of their lives if we weren’t (Terrell 2015: 190–191).

To survive and reproduce, organisms must take in more energy than they expend, a principle of behavioral ecology called economy of action. Social baseline theory (SBT), a framework based on this principle, organizes decades of observed links between social relationships, health, and well-being, in order to understand how humans utilize each other as resources to optimize individual energy expenditures. (Coan and Maresh 2014: 221).

Furthermore, there is the matter of time. It may be true that time is money, but we humans are pretty good at wasting time for apparently no good reason, energetic or otherwise. And certainly there is no denying that when we feel safe and secure, many of us are willing to invest both time and energy in seemingly unproductive ways.

Consider, for example, the metabolic cost of the continuing mental activity in what has been dubbed the brain’s default mode network (DMN) when we are not task-engaged. The reward of not having to attend closely to the practicalities of the world around us when we feel safely embedded in nurturing social networks may be the excitement Alice must have felt in Lewis Carroll’s story after she had slipped through the looking-glass to explore the hidden wonders to be found therein (although judging by his singular account, Alice evidently did not find doing so as addictive as some today find the similar cognitive experience of playing online computer games). Just as those incarcerated in our penal system may be given time off for good behavior, so too, sharing the demands and burdens of life with others gives us time off to play with whatever takes our fancy on that landscape between our ears.

Previously in this series:
"Thinking about thinking 1. Cognitive niche construction"
"Thinking about thinking 2. Through the looking-glass"
"Thinking about thinking 3. Free will"

Amundson,  Ron (2014). Charles Darwin’s reputation: How it changed during the twentieth-century and how it may change again. Endeavour 38: 257–267.

Beckes, Lane and James A. Coan (2011).  Social baseline theory: The role of social proximity in emotion and economy of action.  Social and Personality Psychology Compass 5: 976–988.

Bowles, Samuel and Herbert Gintis (2011). A Cooperative Species: Human Reciprocity and Its Evolution. Princeton: Princeton University Press.

Coan, James A. and Erin L. Maresh (2014). Social baseline theory and the social regulation of emotion, pages 221–236. In J. Gross, ed., The Handbook of Emotion Regulation, 2nd. ed., pp. 221–236. New York: Guilford Press.

Coan, James A. and David A. Sbarra (2015). Social baseline theory: The social regulation of risk and effort. Current Opinion in Psychology   1: 87–91.

Pinker, Steven (2011a). The Better Angels of Our Nature: The Decline of Violence in History and its Causes. New York: Viking.

Pinker, Steven (2011b). Taming the devil within us. Nature  478: 309–311,

Potter, Stephen (1947). Theory and Practice of Gamesmanship. New York: Henry Holt & Company.

Rand, David G., Corina E. Tarnita, Hisashi Ohtsuki, and Martin A. Nowak (2013). Evolution of fairness in the one-shot anonymous Ultimatum Game.  Proceedings of the National Academy of Sciences U.S.A. 110:  2581–2586.

Ruse, Michael (2014). Was there a Darwinian revolution? Yes, no, and maybe! Endeavour 38: 159–168.

Terrell, John Edward (2015). A Talent for Friendship: Rediscovery of a Remarkable Trait. Oxford and New York: Oxford University Press.

Wilson, Edward O. (2012). The Social Conquest of the Earth. New York: Liveright (a division of W. W. Norton).

John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

Gabriel Stowe Terrell is a freelance writer living in Madison, Wisconsin.




© 2015 John Edward Terrell and Gabriel Stowe Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.

Thinking about thinking 3. Free will

John Edward Terrell and Gabriel Stowe Terrell

Please note: this commentary, recovered on 9-Jan-2017, was originally published in Science Dialogues on 24-March-2015.

THE BEHAVIORIST B. F. SKINNER was famously opposed to “mentalistic explanations” for human behavior. By this he meant attributing to the world of the mind an active “top-down” role (Baumeister and Miller 2014) in determining what we think, say, and do. In his eyes, trying to explain our overt behavior by appealing to inner states of mind, feelings, and other elements of an “autonomous man” inside our skulls was utterly foolish, unscientific, and a waste of time. “The ease with which mentalistic explanations can be invented on the spot is perhaps the best gauge of how little attention we should pay to them” (Skinner 1971: 160).

Instead, according to Skinner, the “task of a scientific analysis is to explain how the behavior of a person as a physical system is related to the conditions under which the human species evolved and the conditions under which the individual lives” (1971: 14). As distasteful as some might find such a realization, “the fact remains that it is the environment which acts upon the perceiving person, not the perceiving person who acts upon the environment” (1971: 188).

Even Skinner was willing to concede the “indisputable fact of privacy.” Nonetheless he stuck to his staunch environmentalism. “It is always the environment which builds the behavior with which problems are solved, even when the problems are to be found in the private world inside the skin” (1971: 194).

In a scathing review of Skinner’s 1971 book Beyond Freedom and Dignity, the linguist Noam Chomsky thoroughly rejected Skinner’s scientific claims. “His speculations are devoid of scientific content and do not even hint at general outlines of a possible science of human behavior. Furthermore, Skinner imposes certain arbitrary limitations on scientific research which virtually guarantee continued failure” (Chomsky 1971).

Unfortunately Chomsky’s spirited defense of human freedom and dignity against Skinner’s denial of both offered few concrete hints on why we are not the automatons Skinner said we are. But how are we not controlled by the world around us and by all that life deals us, both painful and pleasurable? How and how much does Skinner’s nemesis “autonomous man” have any real say in what we think, feel, and do? Chomsky left these critical issues unexplored and undocumented.

The mind-body problem

The philosopher Jerry Fodor noted in 1980 that traditional philosophies of mind can be divided into two sorts: dualist theories and materialist theories. “In the dualist approach the mind is a nonphysical substance. In materialist theories the mental is not distinct from the physical; indeed, all mental states, properties, processes and operations are in principle identical with physical states, properties, processes and operations” (Fodor 1980: 114). Since then cognitive psychologists and experts in neuroscience imaging have come down more or less firmly on the side of materialist theories, although exactly how the neurological hardware and software called the brain processes information and arrives at conclusions remains more an educated guess than a demonstrated reality.

Awkwardly what has traditionally been called the “mind-body problem” has often been seen in both science and philosophy as a conundrum about the consciousness of our thoughts and decisions. Yet as Max Velmans (2008) has observed, “it is now clear that ‘mind’ is not quite the same thing as ‘consciousness,’ and that the aspect of body most closely involved with consciousness is the brain. It is also clear that there is not one consciousness–brain problem, but many.” In other words, reading “mind and body” to mean “consciousness and brain tissue” is far too restrictive, too limiting.

Recently Ralph Adolphs (2015) at the California Institute of Technology surveyed what we do and don’t know about consciousness as a mental phenomenon and finds that there is little agreement about what it is and how it works. He helpfully divides the unsolved problems in neuroscience into four basic categories ranging from those that are now solved or will soon be to those that may never be decided. Discouragingly, he puts three key issues in the latter category. (1) How does the human brain compute? (2) How can cognition be so flexible and generative? (3) How and why does conscious experience arise?

His final conclusion is equally sobering. “In a nutshell, then, the biggest unsolved problem is how the brain generates the mind, conceived of in a way that does not simultaneously require answering the problem of consciousness.” However, on a more promising note, he adopts the framework proposed by David Marr (1982) to suggest that memory at least can be understood as the “ability to predict the future by learning.”

This comment is worth emphasizing. Unlike old Father William in Lewis Carroll’s famous poem who elected to stand on his head again and again after learning he had no brain, we see the design and decision-making that are both so fundamental to human niche construction as tangible proof that the human brain is capable of stimulus-independent, self-directed thought (Bonn 2013)—a roundabout way of saying that like Father William, the cognitive manipulations and innovations happening in our minds can lead to top-down, not just bottom-up causation (Foulkes and Domhoff 2014).

Evidence favoring this admittedly far from surprising conclusion can be seen readily enough in what happens on the landscape between our ears during that mysterious cognitive activity called dreaming.

Dreams and dreaming
Sir John Tenniel’s hand-colored proof of Cheshire Cat in the Tree Above Alice for The Nursery “Alice”, ca. 1889.

It is an enduring folk belief that we live our lives on-again off-again in dichotomous ways. We are either happy or sad, awake or asleep, conscious or unconscious, rational or emotional, and so on.

Cognitive psychology today, however, is discovering that a great deal that is happening in the brain instrumental to our survival, success, and emotional well-being is (1) largely disengaged from our conscious awareness of what’s going on both inside and outside us (e.g., Mudrik et al. 2014; Soto and Silvanto 2014), and is (2) more dependent on our feelings and emotions than conventionally seen (e.g., Inzlicht et al. 2015).

Dreaming, like consciousness, is one of those arenas of mental life about which much has been written and yet much remains to be understood (Domhoff and Fox 2015). Here we offer two observations. First, dreaming is more a top-down brain activity than generally envisioned (Foulkes and Domhoff 2014). Second, nobody who has ever recalled a dream needs to be told by anyone else that our brains are capable of creating often credible but truly off-the-wall situations, scenarios, and storied experiences that may not only have lingering emotional impact long after awakening, but can also be a source of great inspiration and creative insight. In short, cognitive niche construction does not need to be either conscious or wakeful.

Free will

Saying you know for sure what free will is or isn’t has long been a reliable way of provoking debate (Monroe et al. 2014). Nonetheless, here are three claims based on what we have been discussing thus far in this SCIENCE DIALOGUES series. First, human beings can think about things and actions—past, present, or future—without being aware that they are doing so (Bonn 2013). Second, human beings can act in accord with the worlds they construct for themselves in their Leslie minds. Third, free will does not have to be rational if by rational we mean “makes sense” in terms of the external world and the laws of physics, etc. Cognitive niche construction may begin with our own experiences of the world, but it does not have to end there. And as we shall discuss in later commentaries in this series, therein lies a problem.

Forthcoming in this series: "Thinking about thinking 4. Our social baseline."
Previously in this series: 
"Thinking about thinking 1. Cognitive niche construction"
"Thinking about thinking 2. Through the looking-glass"

Adolphs, Ralph (2015). The unsolved problems of neuroscience. Trends in Cognitive Science, in press.

Buschman, Timothy J. and Earl K. Miller (2014). Goal-direction and top-down control. Philosophical Transactions of the Royal Society B: Biological Sciences 369: 20130471

Bonn, Gregory B. (2013). Re-conceptualizing free will for the 21st century: Acting independently with a limited role for consciousness. Frontiers in Psychology 4: 920. doi: 10.3389/fpsyg.2013.00920

Chomsky, N. (1971). The case against B. F. Skinner. The New York Review of Books 17: 18-24.

Domhoff, G. William and Kieran C. R. Fox (2015). Dreaming and the default network: A review, synthesis, and counterintuitive research proposal. Consciousness and Cognition 33: 342–353.

Fodor, Jerry (1880). The mind-body problem. Scientific American244/1: 114–123.

Foulkes, David and G. William Domhoff (2014). Bottom-up or top-down in dream neuroscience? A top-down critique of two bottom-up studies. Consciousness and Cognition 27: 168–171.

Inzlicht, Michael, Bruce D. Bartholow, and Jacob B. Hirsh (2015). Emotional foundations of cognitive control. Trends in CognitiveScience 19: 126–132.

Marr, David (1982). 9 Marr, D. (1982) Vision: A Computational Investigation into the Human Representation and Processing of Visual Information. San Francisco: W. H. Freeman.

Monroe, A. E., Dillon, K. D., and Malle, B. F. (2104). Bringing free will down to earth: People’s psychological concept of free will and its role in moral judgment. Consciousness and Cognition 27: 100–108.

Mudrik, Liad, Nathan Faivre, and Christof Koch (2014). Information integration without awareness. Trends in Cognitive Sciences 18: 488–496.

Skinner, B. F. (1971). Beyond Freedom and Dignity. New York: Alfred A. Knopf, 1972.

Soto, David and Juha Silvanto (2014). Reappraising the relationship between working memory and conscious awareness. Trends in Cognitive Sciences 18: 520–525.

Velmans, Max (2008). How to separate conceptual issues from empirical ones in the study of consciousness. In R. Banerjee and B. K. Chakrabarti (eds.), Models of Brain and Mind: Physical, Computational and Psychological Approaches 168: 1–9.


We thank Tom Clark and Kevin Kelly for their comments and suggestions for improvement.

John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

Gabriel Stowe Terrell is a free-lance writer living in Madison, Wisconsin.




© 2015 John Edward Terrell and Gabriel Stowe Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.

Thinking about thinking 2. Through the looking-glass

 John Edward Terrell and Gabriel Stowe Terrell

Please note: this commentary, recovered on 9-Jan-2017, was originally published in Science Dialogues on 5-March-2015.


“Oh, Kitty! how nice it would be if we could only get through into Looking-glass House! I’m sure it’s got, oh! such beautiful things in it! Let’s pretend there’s a way of getting through into it, somehow, Kitty. Let’s pretend the glass has got all soft like gauze, so that we can get through. Why, it’s turning into a sort of mist now, I declare! It’ll be easy enough to get through—” She was up on the chimney-piece while she said this, though she hardly knew how she had got there. And certainly the glass was beginning to melt away, just like a bright silvery mist.

Through the Looking-Glass by Lewis Carroll, 1871

 ALICE’S ADVENTURES IN WONDERLAND (first published in 1865) is Lewis Carroll’s most beloved book thanks in part to Walt Disney Studios and its 1951 cartoon version that  beautifully captured the logical nonsense of Carroll’s rich fantasy world of talking rabbits, smiling cats, and unlikely occurrences. The Disney cartoon, however, also incorporated a few of the characters and events from Carroll’s sequel Through the Looking-Glass and What Alice Found there (1871).

While both books exhibit his brilliance at cognitive niche construction, Carroll’s framing his second story around the otherworldly semblance of reality seen in a looking-glass may have been inspired by his own reflections on the elusiveness of human thought. He was a mathematician first and foremost. He knew well that however much our thoughts may mirror the world around us and what we experience from the cradle to the grave, each of us lives in a cognitive world populated by our own private thoughts on the “other side of the looking-glass”—a world that, unlike Alice, others cannot enter and explore.

The human conundrum

There is nothing surprising about saying we can draw a line between our public lives and our private thoughts. Look into the eyes of any dog. There is also nothing remarkable about saying  we are evidently not the only species capable of entertaining private thoughts and passions. As one of us has explored more fully elsewhere (Terrell 2015), our evolved human capacity to engage in cognitive niche construction—however remarkable or shared with at least some other species—brings with it costs as well as benefits. Socially we have evolved as a species to both want and need human contact and engagement. Yet during the evolution of our huge human brain we achieved a level of private cognition that enables us to disengage from the world around us. Hence as a species we are confronted with a conundrum.  We are social creatures with private thoughts “on the other side of the mirror” that can isolate us from others.

Over the course of human evolution there has been a dynamic interplay between our mental & physical abilities, our brains, our social behavior, and our cleverness at niche construction that has also nurtured our skillfulness as a species at cognitive niche construction.
Lou, Laurence, and Leslie

Modeling how our minds work has taken many twists and turns over the course of human history. Some of the more extreme recent interpretations have insisted either that the brain is massively modular in its aptitudes (Steven Pinker and other evolutionary psychologists), or alternatively is passively shaped, or sculpted, by our interactions with the world around us (classical 20th century stimulus-response psychology).

At this stage in our investigations, we prefer to remain agnostic about how the brain’s circuitry gives us the capacity for thinking as seen in all its many dimensions, public and private (Adolphs 2015; Lamme 2006). In keeping with Daniel Kahneman’s (2011) wisdom to use such things as tools for thought rather than as literal descriptions of our cerebral hardware, we find it useful to characterize how we think about things and events in three different ways using the labels LouLaurence, and Leslie (for discussion, see: Terrell 2015: chapter 4):

  • Lou (also known as System 1 or Type 1)—thinking that is unconscious, automatic, quick, perhaps emotional, and easy to do; in short, information processing in the brain done mostly without conscious awareness; a type of thinking that may be evolutionarily old and is probably also within the mental capabilities of other animal species; the realm of our habitual selves.
  • Laurence (called System 2 or Type 2)—thinking that is conscious, slow, takes effort, and is purposeful; usually said to be involved in “higher-order” cognitive processes such as logical reasoning and decision-making; may or may not be unique to our species; the realm of intentional environmental niche construction.
  • Leslie—thinking that is contemplative, abstract, may be counterfactual, and is largely detached from an individual’s immediate realities; may or may not be unique to our species; the realm of cognitive niche construction
THE VISTA ON THE OTHER SIDE OF THE LOOKING-GLASS IN LEWIS CARROLL’S COGNITIVE WORLD WAS CURIOUSLY CARTESIAN! “For some minutes Alice stood without speaking, looking out in all directions over the country—and a most curious country it was. There were a number of tiny little brooks running straight across it from side to side, and the ground between was divided up into squares by a number of little green hedges, that reached from brook to brook.”
Self-generated thought

As Jessica Andrews-Hanna and her colleagues observed recently, understanding the mechanisms underlying self-generated thought and its adaptive and maladaptive functional outcomes has been a key aim of cognitive science in recent years (Andrews-Hanna et al. 2014: 29). In their estimation, far from being a passive brain phenomenon, for example, the default mode network (DMN) within our skulls contributes to several active forms of internally driven cognition. As she and her colleagues have written:

Tasks that activate the network often require participants to retrieve episodic, autobiographical, or semantic information, think about or plan aspects of their personal future, imagine  novel scenes, infer the mental states of other people, reason about moral dilemmas or other scenarios, comprehend narratives, self-reflect, reference information to one’s self, appraise or reappraise emotional information, and so on. (Andrews-Hanna et al. 2014: 32)

Although much remains to be learned about the costs and benefits of self-generated thought—which has also been dubbed stimulus-independent thought, spontaneous thought, internally-directed thought, and mind-wandering—it is becoming increasingly clear that the default and executive networks in the brain are not inherently working in opposition.

Kalina Christoff and her colleagues, as a case in point, have argued that both networks can work in parallel in ways that are reminiscent of the neural recruitment observed during creative thinking before solving problems with insight. Furthermore, “similar parallel recruitment of executive and default regions has also been observed during naturalistic film viewing, which is related to immersive simulative mental experience” (Christoff et al. 2009: 8723).

What we find both intriguing and frustrating  is that many researchers studying self-generated thought, with notable exceptions (Killingsworth and Gilbert 2010), seem committed to the view that internally-directed thought lies within the reach of human cognition because even when it appears to be getting us away from what we really ought to be doing to survive and make a living, mind-wandering may nonetheless “enable the parallel operation of diverse brain areas in the service of distal goals that extend beyond the current task” (Christoff et al. 2009: 8723).

Perhaps, but not necessarily so, as we shall discuss in the next commentary in this series.

Previously in this series: “Thinking about thinking 1: Cognitive niche construction”  Next in this series“Thinking about thinking 3. Free will”


Adolphs, Ralph (2015). The unsolved problems of neuroscience. Trends in Cognitive Sciences, in press.

Andrews‐Hanna, Jessica R., Jonathan Smallwood, and R. Nathan Spreng (2014). The default network and self‐generated thought: Component processes, dynamic control, and clinical relevance. Annals of the New York Academy of Sciences 1316: 29–52.

Christoff, Kalina, Alan M. Gordon, Jonathan Smallwood, Rachelle Smith, and Jonathan W. Schooler (2009). Experience sampling during fMRI reveals default network and executive system contributions to mind wandering. Proc. Natl. Acad. Sci. U.S.A. 106: 8719–8724.

Kahneman, Daniel (2011). Thinking: Fast and Slow. New York: Farrar, Straus and Giroux.

Killingsworth, Matthew A., and Daniel T. Gilbert (2010). A wandering mind Is an unhappy mind. Science 330: 932.

Lamme, Victor A. F. (2006). Towards a true neural stance on
consciousness. Trends in Cognitive Sciences 10: 494–501.

Terrell, John Edward (2015). A Talent for Friendship: Rediscovery of a Remarkable Trait. Oxford and New York: Oxford University Press.

John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

Gabriel Stowe Terrell is a freelance writer living in Madison, Wisconsin.




© 2015 John Edward Terrell and Gabriel Stowe Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.

Thinking about thinking 1. Cognitive niche construction

John Edward Terrell 

Please note: this commentary, recovered on 9-Jan-2017, was originally published in Science Dialogues on 22-Jan-2015.

“Can we state more distinctly still the manner in which the mental life seems to intervene between impressions made from without upon the body, and reactions of the body upon the outer world again?”

William James, The Principles of Psychology, 1890: 6

By Dmitry Rozhkov (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons
THE NEUROLOGIST MARCUS RAICHLE HAS remarked that studies of brain function have traditionally focused on task-evoked responses (Raichle 2010, 2015). As Daniel Kahneman has explained, such research has contributed the useful convention that there are two modes of thinking—two systems in the mind, System 1 (or Type 1) and System 2 (or Type 2). In Kahneman’s words (2011: 20–21):

System 1 operates automatically and quickly, with little or no effort and no sense of voluntary control.

System 2 allocates attention in the effortful mental activities that demand it, including complex computations. The operations of System 2 are often associated with the subjective experience of agency, choice, and concentration.

Although such conventions are useful, Raichle argues that focusing on task-evoked responses “ignores the alternative possibility that brain functions are mainly intrinsic, involving information processing for interpreting, responding to and predicting environmental demands” (2010: 180).

As he says, it is not difficult to see why so much attention has been given to monitoring neural responses to carefully designed tasks that can be rigorously controlled: “evaluating the behavioral relevance of intrinsic activity (i.e. ongoing neural and metabolic activity which is not directly associated with subjects’ performance of a task) can be an elusive enterprise” (2010: 180).

While it could be argued that intrinsic brain tasks are part and parcel of System 2 thinking, I believe it may be more constructive to infer instead that there is a third mode of thinking—one that I have suggested may be called cognitive niche construction (Terrell 2015: 29–32, 168–172)—a way of thinking that may strongly engage the brain’s default-mode network.

Default-mode network

As Raichle (2015) and Robert Spunt and his colleagues (in press) have underscored, there is considerable metabolic cost to running the human brain when it is engaged in ongoing internal activity. As the latter researchers observe: “most of the brain’s energy budget is consumed not by activity evoked by specific cognitive tasks (e.g., mental arithmetic) but by spontaneous ongoing activity that is most notable when the brain is at rest.”

Given the metabolic cost of this ongoing internal activity in what has been dubbed the brain’s default mode network (DMN) when we are not task-engaged, an obvious question arises. How can we afford such stimulus-independent activity?

Raiche, Spunt et al., and others stress the likelihood that such inner-directed brain activity must be somehow adaptive in a realistic Darwinian sense, i.e., this inner activity must be “functionally consequential for the execution of stimulus-dependent mental state inferences” (Spunt et al. in press). This inference is plausible, but arguably not sufficient.

Niche construction

How we are able to remake the world around us when we put our minds and backs to the effort has been called niche construction (Odling-Smee et al. 2003). In the biological sciences, the word “niche” means “way of life,” and every species is said to have its particular place, or niche, in the economy of life. We are just one of a number of species that excel at making and remaking their way of life, their place in the grand scheme of things, their ecological niche. Similarly, I have argued that even when it may look as if we are day-dreaming, our minds actually may be hard at work engaged in cognitive niche construction—a way of using our brains that is possibly but not necessarily unique to our species (Terrell 2015).

Others recently have also written about cognitive niche construction, but what they evidently have in mind may be more clearly activity under the heading of System 2 thinking. Steven Pinker, for instance, has defined cognitive niche construction as “a mode of survival characterized by manipulating the environment through causal reasoning and social cooperation” (Pinker 2010: 8993).

Such a description glosses over how difficult it can be to apply what we envision in our mind’s eye to the realities of life. More to the point, such a definition does not confront the obvious weakness of cognitive niche construction at least as I have described it. What goes on between our ears when we are engaged in such mental activity does not have to be rational at all, at least not if by “rational” we mean thinking that makes practical sense in the real world outside our bodies.

A Paradox

By detaching from the realities of the moment and turning our mind to our inner thoughts, we are able to ponder what I like to call the “coulds & shoulds” of life. We can devote our mind to a kind of imaginary niche construction that does not even have to be “of this world” at all. We can see seemingly impossible things in our mind’s eye. We can engage in “what if” fantasies of remarkable, perhaps sexually charged, and even quite unrealistic complexity. We can invent imaginary worlds, invent new things, rewrite the story of our life to our heart’s content. All in the mind rather than in the real world.

In short, it seems likely we engage in cognitive niche construction not just for interpreting, responding to, and predicting environmental demands—to paraphrase what Raichle has previously said. As Spunt et al. observe: “Given that the DMN activity is metabolically costly, widely distributed in the cortex, and highly sensitive to both the presence and type of task demand, it should be no surprise that this network would have functional consequences in multiple domains” (Spunt et al., in press).

They themselves hypothesize that natural selection has favored the evolution of such a costly DMN in humans (and possibly also in chimpanzees and monkeys) so that we can more skillfully “see the world in terms of other minds” and live together socially—thereby gaining far more socially than would be likely by living separately.

While this is a plausible hypothesis, it is not the only one possible, as Gabriel Terrell and I will discuss in the forthcoming commentaries.

Editor’s note: This is the first in a series of eight commentaries at SCIENCE DIALOGUES on cognitive niche construction and its implications for psychology, philosophy, and the social sciences generally.

Next in this series: “Thinking about thinking 2. Through the looking-glass.”


Kahneman, Daniel (2011). Thinking: Fast and Slow. New York: Farrar, Straus and Giroux.

Odling-Smee, F. John, Kevin N. Laland, and Marcus W. Feldman (2003). Niche Construction. Princeton: Princeton University Press.

Pinker, Steven (2010). The cognitive niche: Coevolution of intelligence, sociality, and language. Proceedings of the National Academy USA 107, suppl. 2: 8993–8999.

Raichle, Marcus (2010). Two views of brain function. Trends in Cognitive Sciences 14: 180–190.

Raichle, Marcus (2015). The restless brain: How intrinsic activity organizes brain function. Philosophical Transactions of the Royal Society B 370: 20140172.

Spunt, Robert P., Meghan L. Meyer, and Matthew D. Lieberman (in press). The default mode of human brain function primes the intentional stance. Journal of Cognitive Neuroscience.

Terrell, John Edward (2015). A Talent for Friendship: Rediscovery of a Remarkable Trait. Oxford and New York: Oxford University Press.

John Edward Terrell is Regenstein Curator of Pacific Anthropology at The Field Museum, Chicago, IL 60605. His latest book A Talent for Friendship: Rediscovery of a Remarkable Trait was published on December 1, 2014 by Oxford University Press. Email address: terrell[at]

© 2015 John Edward Terrell. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. The statements and opinions expressed are those of the author(s) and do not constitute official statements or positions of the Editors and others associated with SCIENCE DIALOGUES.