Cecilia Heyes - Cognitive Gadgets: The Cultural Evolution of Thinking

C O G N I T I V E G A D G E T SC O G N I T I V EG A D G E T S The Cultural Evolution of Thinking Cecilia Heyes THE BELKNAP PRESS OF HARVARD UNIVERSITY PRESS Cambridge, Mas sa chu setts London, England 2018 Copyright 2018 by the President and Fellows of Harvard College All rights reserved Printed in the United States of Amer i ca First printing Library of Congress Cataloging- in- Publication Data Names: Heyes, Cecilia M., author. Title: Cognitive gadgets : the cultural evolution of thinking / Cecilia Heyes. Description: Cambridge, Mas sa chu setts : The Belknap Press of Harvard University Press, 2018. | Includes bibliographical references and index. Identifiers: LCCN 2017041745 | ISBN 9780674980150 (hardcover : alk. | Nature and nurture. | Social evolution. | Evolutionary psy chol ogy. | Evolutionary psy chol ogy.

Classification: LCC BF311 .H46916 2018 | DDC 155.7 dc23 LC rec ord available at https:// lccn .loc .gov / 2017041745 Jacket design: Lisa Roberts In memory of Donald T. Campbell Contents C O G N I T I V E G A D G E T SWHAT MAKES US SUCH PECULIAR ANIMALS? Compared with other creatures, we humans lead very strange lives. No other animals have so completely transformed their environment, become so dependent on cooperation for survival, and constructed, along the way, the vast edifices of knowledge and skill in which all human lives are embedded: technology, agriculture, science, religion, law, politics, trade, history, art, lit er a ture, music, and sports. Why? What is it about the human mind that enables us to live such unusual lives, and why do our minds work that way? In this book I argue that the answer to these questions is cognitive gadgets. We humans have created not just physical machines such as pulleys, traps, carts, and internal combustion engines but also mental machines; mechanisms of thought, embodied in our ner vous systems, that enable our minds to go further, faster, and in dif er ent directions than the minds of any other animals. These distinctively human cognitive mechanisms include causal understanding, episodic memory, imitation, mindreading, normative C O G N I T I V E G A D G E T S thinking, and many more.

They are gadgets, rather than instincts (Pinker, 1994), because, like many physical devices, they are products of cultural rather than ge ne tic evolution.1 New cognitive mechanisms dif er ent ways of thinking have emerged, not by gene tic mutation, but by innovations in cognitive development. These novelties have been passed on to subsequent generations, not via genes, but through social learning; people with a new cognitive mechanism passed it on to others through social interaction. And some of the new ways of thinking have spread through human populations, while others have died out, because the holders had more students, not just more babies (Sober, 1991). Psychologists often use gadgets as meta phors. They suggest that vari ous aspects of the human mind operate in the same way as cir cuit boards, cisterns, search lights, search engines, thermostats, resistors, and the bristles of a Swiss Army knife. But, if I am right, the resemblance runs much deeper.

Distinctively human ways of thinking are products of the same process cultural evolutionas machines in the outside world; they are pieces of technology embodied in the brain. Ge ne tic evolution has given humans more power ful general purpose mechanisms of learning and memory, tweaked our temperaments, and biased our attention so that it is focused on other people from birth. But drawing on comparative and developmental psy chol ogy, cognitive neuroscience, philosophy, anthropology, behavioral economics, and theoretical biology I argue in this book that it is the information we get from others, handled by general purpose mechanisms, that builds distinctively human ways of thinking. The first three chapters lay some foundations for cultural evolutionary psy chol ogy. Chapter 1 says more about the cognitive gadgets theory what it is, and what it is not explaining how and why cultural evolutionary psy chol ogy builds on evolutionary psychol ogy and cultural evolutionary theory. Chapter 2 draws on the phi Introduction 3 losophy of biology, arguing that, although we now know that some versions of the nature nurture debate were deeply misguided, it is impor tant to discover, for any par tic u lar feature of human cognition, the ways and extent to which the feature is shaped by: (1) genet ically inherited information; (2) culturally inherited information; and (3) information derived directly from the environment in the course of development.

Chapter 2 also includes an overview of con temporary cultural evolutionary theory, showing how it can be applied, not only to cognitive products (grist), but also to cognitive mechanisms (mills). Chapter 3 focuses on features of distinctively human cognition that have been shaped primarily by genet ically inherited information. It surveys behavioral and neurological evidence that, far from being blank slates, or just like the minds of chimpanzees, the minds of newborn human babies are equipped with high capacity mechanisms of learning and memory, species specific attentional mechanisms, and a tendency to find social cues especially rewarding. Chapter 4 examines the nature of cultural learning that enables cultural inheritance the cultural analogue of DNA replication and provides an introduction to the heart of the book, Chapters 58. Each of these chapters examines a type of cultural learning (selective social learning, imitation, mindreading, and language) and argues, from the available evidence, that its distinctively human characteristics depend on culturally inherited information. I focus on the mechanisms of cultural learning the cognitive gadgets that enable humans to learn from others with extraordinary efficiency, fidelity, and precision for two reasons.

First, these distinctively human cognitive mechanisms are especially impor tant because they are gifts that go on giving: culturally inherited skills that enable the cultural inheritance of more skills. Second, evolutionary psychologists and cultural evolutionists disagree about the origins of many cognitive characteristics, but both parties are convinced that the mechanisms C O G N I T I V E G A D G E T S of cultural learning are cognitive instincts, not cognitive gadgets. This consensus suggests that the mechanisms of cultural learning are the hardest nuts to crack the cognitive mechanisms that are least likely to be explicable as products of cultural evolution. Social learning is said to be selective, or to involve social learning strategies, when the impact on be hav ior of observing another agent varies with the circumstances in which the encounter occurs, or with the characteristics of the observed agent, or model for example, when older models have more impact than younger models. In Chapter 5, I argue that most selective social learning found in nonhuman animals, children, and adultsis due to domain general learning and attentional pro cesses, that is, to pro cesses that have not been specialized for social interaction, let alone for cultural inheritance. However, a small proportion of social learning strategies, found only in adult humans, depend on explicit metacognitionon thinking about thinking.

These, and only these, behavioral efects are genuinely strategic, and genuinely examples of cultural learning. The evidence suggests that, like other explicitly metacognitive rules, these metacognitive social learning strategies are learned through social interaction culturally, rather than genet ically, inherited. Imitation occurs when an observer copies the topography of a models action; observing the way that parts of a models body move