We examine the ontogeny and phylogeny of object and fantasy play from a functional perspective. Each form of play is described from an evolutionary perspective in terms of its place in the total time and energy budgets of human and nonhuman juveniles. As part of discussion of functions of play, we examine sex differences, particularly as they relate to life in the environment of evolutionary adaptedness and economic activities of human and nonhuman primates. Object play may relate to foraging activities. (...) Although fantasy play has been viewed as limited to humans, we speculate that certain types of fantasy play may be present in some nonhuman primates. Fantasy play may enable juveniles to see situations from different perspectives. We conclude that fantasy play may have immediate effects and object play may have deferred effects. (shrink)

Certain characteristics of childhood immaturity (e.g., infantile facial features) may have been favored by natural selection to evoke positive feelings in adults. We propose that some aspects of cognitive immaturity might also endear young children to adults. In two studies, adults rated expressions of mature and immature thinking attributed to children. Immature thinking in which children expressed a supernatural explanation elicited positive affect reactions, whereas other forms of immature thinking, which made no attribution to supernatural causation, were responded to negatively. (...) This pattern was found for parents and others, males and females, American and Spanish college students, and for target children 3 to 9 years of age. We suggest that persistence of supernatural thinking in adulthood causes people to view the expressions of such thinking in children in a positive manner, fostering nurturance of young children who display them. (shrink)

Although we find many merits to Grossmann's fearful ape hypothesis, unlike Grossmann, we see heightened fearfulness as an ontogenetic adaptation, signaling helplessness and fostering caregiving during infancy, which subsequently became exapted to promote cooperation. We also argue that, rather than being the “breeding ground” for enhanced infant fearfulness, cooperative care is more likely the evolved product of enhanced fearfulness.

Aspects of cognitive immaturity may serve both to adapt children to their immediate environment and to prepare them for future ones. Language may have evolved in children's groups in the context of play. Developmental plasticity provides variability upon which natural selection operates, and such plasticity, that likely played an important role in the evolution of language, characterizes human children today.

The aim of this study was to explore the role of voices as cues to adults of children’s needs for potential caregiving during early childhood. To this purpose, 74 college students listened to pairs of 5-year-old versus 10-year-old children verbalizing neutral-content sentences and indicated which voice was better associated with each of 14 traits, potentially meaningful in interactions between young children and adults. Results indicated that children with immature voices were perceived more positively and as being more helpless than children (...) with mature voices. Children’s voices, regardless of the content of speech, seem to be a powerful source of information about children’s need for caregiving for parents and others during the first six years of life. (shrink)