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Long neglected by researchers, metacognition has made its way to the scientific spotlight

Know Thyself: The Science of Self-Awareness

Stephen M. Fleming
Basic Books
2021
304 pp.
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For millennia, religious thinkers and philosophers have cited humanity’s self-awareness—that is, our ability to think about our own mind and character—as being key to the uniqueness of our species. Carl Linnaeus’s groundbreaking biological taxonomy (1) likewise characterized our genus by the words “Homo. Nosce te ipsum” (“Man. Know thyself”).

Given our long-standing interest in self-awareness, it is surprising how little science has traditionally had to say about it. What features of our brains enable us to think about ourselves? What are our strengths and weaknesses in this respect and how do they influence how we decide, learn, and interact? Can we train self-awareness, and how does this improve our performance? In the past three decades, however, research addressing such questions has been picking up speed. In Know Thyself, cognitive neuroscientist Stephen Fleming synthesizes this multifaceted research into an admirably coherent narrative and outlines how the resulting knowledge may be applied to solve societal problems.

Writing about self-awareness is challenging because concepts such as “self” and “awareness”—let alone the combination thereof—are hard to define. The book does not get lost in this epistemological Bermuda triangle but rather conceptualizes self-awareness as the set of mental and brain processes that keep track of our percepts, thoughts, and actions.

Not all of these metacognitive processes concern the self in a philosophical sense, Fleming notes, and not all of them need to be conscious. A helpful metaphor in the book compares the human brain to a flying plane that is largely guided by autopilot technology but can be flexibly controlled by the pilot whenever needed. For our behavior, the autopilot is the unconscious, “implicit” part of metacognition, and the pilot is the “explicit” metacognition that we can consciously report.

Fleming begins by summarizing the psychology and neuroscience of these metacognitive processes. Implicit metacognition, he notes, is evident in many seemingly low-level brain processes, ranging from the sensory brain cells that signal the uncertainty associated with particular percepts, to brain cells that activate when we commit action errors (think: mistyping on a keyboard). All of these implicit signals can be read out in the service of explicit metacognition, when, for example, we need to judge our confidence in having chosen the right action. This latter ability depends on specific brain areas in the prefrontal cortex and is independent of the basic perceptual and motor abilities it serves to monitor.

Explicit metacognition, meanwhile, depends on our ability to think about the mental states of others—an ironic twist nicely summarized by the caption of a cartoon that appears in the book: “Of course I care about how you imagined I thought you perceived I wanted you to feel.”

It is eye-opening to realize how many fields of human endeavor depend not just on our skills and knowledge but also on our ability to estimate our competence. Obvious examples can be found in education, politics, the legal system, corporate decision-making and leadership, news and social media, and, indeed, any collaboration in which people pool their expertise. The book illustrates the role of metacognition in these diverse fields with elegant combinations of philosophical considerations, basic science findings, and more applied examples.

Fleming even ventures into the near future, sketching how artificial intelligence with superhuman computational abilities but no self-awareness may become disconnected from humanity at best and outright catastrophic at worst. Emerging ideas on how we may address this problem—for example, by endowing intelligent machines with coarse self-awareness or by ensuring that self-aware humans remain at the helm—only serve to prove how little we have appreciated our own prodigious metacognitive abilities.

In the end, the book makes a convincing case that self-awareness is a key feature of human existence and that our growing knowledge about it will be important for addressing many of our societal problems. One may quibble that the book somewhat understates this point, because it focuses on metacognition and does not cover our ability to monitor our emotions, another key aspect of self-awareness that has major implications for health and well-being. However, the literature on this topic is so diverse that doing it justice would likely require several additional volumes. As it stands, Fleming’s book finally heaves metacognition into a long-deserved place in the scientific spotlight.

References and Notes:
1. C. Linnaeus, Systema Naturae (Haak, 1735).

About the author

The reviewer is at the Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland.