Review - Origins of Human Nature
Evolutionary Developmental Psychology
by David F. Bjorklund and Anthony D. Pellegrini
American Psychological Association, 2001
Review by Keith S. Harris, Ph.D.
May 29th 2002 (Volume 6, Issue 22)

The authors of this book are already respected and well-published scholars in the field of developmental psychology.  They have written extensively on human development from the “standard social sciences” model.  This current work, as its inner flap explains, is the first book-length attempt to extend evolution-based psychology to developmental psychology.  The authors add, “Although much had been written about psychological developmental issues from an evolutionary perspective, we found no over-arching evolutionary perspective in developmental psychology” (p. 3).  The book’s primary position is explained in this way:  “[A]n understanding of human evolution provides the framework for an understanding of psychological functioning and development” (p. 9). 

For the purposes of this review, the book can be divided into two major sections.  In the first section, which is comprised of five chapters, the principles of general evolutionary psychology are considered and explained, and the concept of evolved adaptations is explicated.  A developmental systems perspective is used to describe gene-environment interactions.  The history of evolutionary theory as it applies to human development is discussed, as are issues of timing (sequencing) and the development of cognitive abilities in primates and humans.  With that grounding, five of the six remaining chapters address specific topics in developmental psychology. 

In Chapter 6 the authors consider what is known and hypothesized about human learning.  The issue of modularity, or domain-specific learning, is fully explored.  This is an especially important area for evolutionary psychologists, because it addresses the question of how and what we can learn, how we think about our world, and even the limits of what can be thought.  Contrary to John Locke’s position that humans are born tabula rasa, all the evidence suggests that infants are born prepared to learn certain tasks and information at specific stages of development, and less disposed to learn other types of information.

Human thought and consciousness is qualitatively different from that of other species.  How have humans come to develop such a robust intellect?  “We believe, as do many others, that the evolution of the human species’ unique intelligence was motivated by the need to deal with other members of our social group” (p. 193).  So begins a very profound chapter on social cognition.  The authors do an excellent job of bringing together and presenting theory and research findings.  The brilliant work of Michael Tomasello and his colleagues is given a prominent position in this chapter.  The important concept known as “theory of mind” deserves, and gets, special attention.  “We view theory of mind as a set of cognitive abilities that are necessary for sophisticated social interaction in human groups” (p. 215).  The hypothesis that the “theory of mind module” (TOMM) itself involves a variety of modules (e.g., an “intentionality detector,” an “eye direction detector,” and a “shared attention module”) provides a very interesting discussion.  The question of whether only humans have “theory or mind” is also considered, with the conclusion that “Despite more than 20 years of research, comparative psychologists have not reached a consensus on whether species other than humans possess the cognitive abilities necessary for theory of mind” (p. 208). 

This observation in the chapter’s summary offers an especially interesting point of view:

When one thinks of the great intellectual accomplishments of the human species, he or she tends to focus on the invention some new form of technology, the discovery of a medical procedure or a cure for a debilitating disease, or on abstract or mathematical discoveries such as Einstein’s theory of relativity.  Yet our species’ most remarkable form of intelligence, at least in the big picture, may be reflected in our day-to-day interactions with other people.  (p. 218)

In the following chapter, the authors discuss Trivers’s now well known parental investment theory, and provide extensions to this theory that bring in the roles of grandparents, alloparents and general public supports in modern societies.  Interesting asides are a discussion of birth order and incest avoidance tendencies.

Of particular and practical significance is the authors’ excellent concluding chapter. Here is provided a concise but comprehensive integration of evolutionary principles and standard human developmental psychology.  A relatively brief section of six pages, appropriately entitled, “Basic Principles of Evolutionary Developmental Psychology,” provides a clear statement of what is known and in what direction we should head from here.  The principles are (pp. 335-340):

1.            Evolutionary developmental psychology involves the expression of evolved, epigenetic programs.

2.            An extended childhood is needed in which to learn the complexities of human social communities.

3.            Many aspects of childhood serve as preparations for adulthood and were selected over the course of evolution.

4.            Some characteristics of infants and children were selected to serve an adaptive function at specific times in development and not as preparations for adulthood.

5.            Many, but not all, evolved psychological mechanisms are domain-specific in nature.

6.            Evolved mechanisms are not always adaptive for contemporary people.

For those who already appreciate the perspective of evolutionary psychology, this book will be a welcome integration of developmental issues.  For those whose background is developmental psychology, the book will likewise be a welcome integration of evolutionary principles with the standard social sciences model.

© 2002 Keith Harris
 

Keith Harris, Ph.D.  is a clinical psychologist and supervisor of Victor Valley Behavioral Health Center in San Bernardino county, California. His interests include clinical supervision, the empirical basis for psychotherapy research (and its design), human decision-making processes, and the shaping of human nature by evolutionary forces.