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.

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