ROLE OF EVOLUTION IN DEVELOPMENT

The principle focus of this book is how an evolutionary perspective can provide a better understanding of ontogeny, particularly human ontogeny.

Although we argue that the perspective provided

by

evolutionary develop- mental psychology is a relatively new one, the founders of developmental psychology were also greatly influenced by evolutionary theory. Unlike other subdisciplines of academic psychology that trace their roots back to 19th- century physics, developmental psychology had its origins in 19th-century biology, particularly in the evolutionary thinking of that time (Cairns,

1998).

Contemporary developmental psychologists are often unaware of this connection, or if they are aware of it, see it only as a piece of history and not as a factor influencing modem thought. That may be true to some extent, for explicitly evolutionary thought was excised from mainstream developmental psychology, as were all forms of biological explication, during the middle portion of the

20th

century when behaviorism held sway. None- theless, Darwin had an enduring, if often unrecognized, influence on develop- mental psychology, and the current rediscovery of his ideas reflects only the latest reincarnation of evolutionary thinking in the field.

Charlesworth (1992) listed four general influences that Darwin had on psychology. The first is the recognition that there is substantial continuity

58

THE ORIGINS OF HUMAN NATURE

in mental functioning between animals and humans. The use of animal models for human development, whether they involve the behavior of quail chicks in perceptual development (Lickliter,

1990)

or theory of mind in chimpanzees (Call & Tomasello,

1999),

relies on the implicit assumption of continuity in intellectual functioning across species at particular times in development. The second influence is an emphasis on the importance of individual differences (see the section on individual differences later in this chapter). The third influence is a focus on adaptive behavioral function, and the fourth, expanding methodologies beyond those of psychophysics and introspection popular in early psychology. Yet Darwin’s influence on child developmental theory seems mostly indirect and, according to Charles- worth, weak. Few of the major developmental theorists gave more than lip service to Darwin’s ideas (Baldwin being an exception). But “Darwinian”

should not be viewed as equivalent to “evolutionary,” particularly at the turn of the

20th

century. There were many ideas about evolution that, even if they were associated with Darwin 100 years ago, were not associated with the modern synthesis that would come to define evolutionary thinking in the last two-thirds of the

20th

century, and early developmental psychology was influenced by some of these subsequently discredited ideas (see Charles- worth,

1992;

Morss,

1990;

Surbey, 1998a).

Recapitulation in Psychological Development

Perhaps the evolutionary concept that most permeated the thinking of the earlier child developmentalists was that of recapitulation (Morss,

1990).

Recall from our earlier discussion Haeckel’s notion that “ontogeny recapitulates phylogeny”; that is, evolution of the species can be seen in the ontogeny of individuals, with evolutionary changes being expressed exclusively in terms of additions to the adult form. Whereas Haeckel was concerned with morphological development, psychologists proposed recapit- ulation theories of behavior and mind. In a history of the influence of evolutionary thinking on developmental psychology, Morss (

1990)

listed most of the great developmental theorists in the first half of the

20th

century, including Wilhelm Preyer (1841-1897), Baldwin (1890-1968),

G.

Stanley Hall (1844-1924), Sigmund Freud

(1856-1939),

Arnold Gesell

(1880-

1961), Lev Vygotsky (1896-1934), Piaget (1896-1980), and Heinz Werner ( 1890-1964), as being unduly influenced by recapitulation thinking.

The most explicit of the recapitulation theorists was Hall (1904), who believed that humans were still actively evolving and that the period of adolescence, not adulthood, must provide the jumping-off point for further evolutionary advance.

At

first, this seems contradictory to Haeckel’s claim that evolution proceeds

by

making additions to the adult stage; but Hall viewed adulthood as a period of decline. It was adolescence that was the

true zenith of human development (a claim that may seem particularly odd for anyone rearing an adolescent). Hall acknowledged the identification of earlier stages of phylogeny in the human embryo and young child but extended this argument by proposing that human ontogeny parallels a more recent evolutionary past, specifically in terms of the behavior of humans’

ancestors. Accordingly, Hall believed that the behavior and minds of modem children ages

8-1

2 years old corresponded to adult behavior and thought of prehistoric times.

By

understanding what children are like, we are able to understand what our ancestors were like. Consistent with this theme, Hall advocated hunting and fishing for boys ages

8-12,

activities in which their prehistoric male predecessors would ‘likely have engaged.

Although Hall’s theory was the most extreme in terms of recapitulation thinking, Morss

(1990)

identified important elements of such thinking in other early theorists. For example, the ordering of Freud’s five psychosexual stages-oral, anal, phallic, latency, and genital-was based on explicit reca- pitulation theorizing. According to Freud (cited in Morss, 1990), “Onto- genesis may be regarded as a recapitulation of phylogenesis, in so far as the latter has not been modified by more recent experience. The phylogenetic disposition can be seen at work behind the ontogenetic process’’ (p.

46).

Piaget believed in the “cultural epoch” theory of education, whereby children are brought through progressively more recent stages of civilization. In general, Morss interpreted much of the biological thinking by early develop- mental psychologists as pre-Darwinian, relying on discredited ideas of Haeck- el’s recapitulation theory and Lamarckianism. He also viewed contemporary developmental theory (through the 1980s) as similarly flawed, stating that

“developmental psychology is built upon foundations that are rotten” and based on “outdated notions of a biological-philosophical nature” (p.

227).

As we noted earlier, recapitulation theory has been making a bit of a comeback in cognitive evolutionary theory of late (Langer,

1998,

2000;

McKinney,

1998;

Parker & McKinney, 1999), based primarily on the obser- vations that many aspects of primate cognition can be viewed in terms of Piaget’s stages of cognitive development, with apes progressing further than monkeys and humans further than apes. (These ideas are discussed in greater detail in chapters

4

and

5.)

Nonetheless, few contemporary recapitulationists would agree with the formulations of Hall, Freud, or likely even Piaget, regarding the extent to which ontogeny is proposed to recapitulate phylogeny.

Sociobiology, Neonativists, and Evolutionary Psychology

As

we noted earlier, evolutionary thinking fell out of favor in psychol- ogy during the heyday of behaviorism and remained out of fashion through the early years of the cognitive revolution. There were exceptions, of course.

60 THE ORIGINS OF HUMAN NATURE

For example, in

1974

Freedman published Human Infancy: An Evolutionary Perspective, and two years later Fishbein published Evolution, Development

,

and Children’s Learning. These books reviewed the principles of evolution, human phylogeny, and certain aspects of ontogeny from an evolutionary perspective, but they were ahead of their time, had little impact on the field, and

did

not find a supportive audience until years after they went out of print. Another important class of exceptions concerned psychologists who viewed development from an ethological perspective (Bowlby, 1969;

McGrew,

1972;

see also chapter

9

and discussion below). Generally, most psychologists essentially ignored evolution and biology when trying to under- stand child development. The advent of sociobiology (Dawkins,

1976; E. 0.

Wilson,

1975),

based on the theories of Hamilton

(1964,1966)

and originally developed to explain altruism, put an emphasis on behavior, and many developmental psychologists took notice and began research programs with an explicitly evolutionary perspective (see papers in MacDonald,

1988).

However, for the most part, this research and theorizing stayed outside of the mainstream of developmental psychology.

During the 1980s, a movement apparently independent of ethology gained steam in cognitive development: neonativism. Extending the pioneer- ing work of Chomsky

(1965)

on the nativism and the domain specificity of language, neonativists held, unlike Piaget or the behaviorists, that children come into the world with certain domain-specific knowledge. They know something already, for example, about language (Karmiloff-Smith,

199

1;

Pinker, 1994), objects (Gelman & Williams, 1998; Spelke & Newport, 1998), and social relations (Bowlby,

1969;

Hinde, 1974). Children still require a supportive environment for these abilities to develop, but the seeds of knowledge, if not the knowledge itself, are within the child and present at birth. (More is said about innateness in the following section and about neonativism in chapter

6.)

Concurrent with the rise of neonativism was the field of evolutionary psychology (Barkow et al., 1992; Daly &Wilson, 1988a).

As

we have seen, development was not a major focus of this new discipline, although it was not explicitly excluded, either.

Child

developmentalists increasingly began to take notice of evolutionary psychology and advocated, as we are here, that development can be best understood when looked at from an evolutionary perspective (Bjorklund, 199713; Bjorklund & Pellegrini, 2000; Geary, 1995;

Geary & Bjorklund, 2000; Keller,

2000;

Surbey, 1998a).

And

this

is the topic of the remainder of the book. Although we realize that there is more than one evolutionary perspective and that there remain many controversies about the relations between ontogeny and phylogeny (among other issues), we believe that biology has returned to the mainstream of developmental explication and with it a tolerance, at least, and an ardor, at best, for evolutionary thinking.

WHAT DOES IT MEAN WHEN WE SAY