Precocious Knowledge of Trees as Antipredator Refuge in Preschool Children: An Examination of Aesthetics, Attributive Judgments, and Relic Sexual Dinichism

Abstract

In simulations of predator avoidance, 3 experiments examined whether preschool children with virtually no tree-climbing experience exhibit precocious knowledge of what different tree shapes afford as climbable refuge. Sex difference in the choice of arboreal or terrestrial refuge was also evaluated with the aim of detecting evidence of ancestral sexual dinichism, the differential use of trees by hominid males and females thought to have occurred more than 2 million years ago when females were much lighter bodied than males and thus more agile tree climbers. Preschool girls were predicted to seek refuge in a tree to escape a predator; boys were predicted to seek terrestrial refuge. When shown pictures of trees, girls were also predicted to be more cognizant than boys of the safety of seeking refuge near the edge of the crown to evade a heavy bodied predator. In Experiment 1, 4- to 6-year-old Israeli children were shown a series of computer-generated pictures of a boulder outcrop (kopje) in an East African savanna setting. Individual children viewed narrated scenes of entering and leaving a narrow crevice, climbing a large boulder, and climbing an acacia tree. They were then shown a picture of a male lion and randomly ordered views of the lion from each refuge, and asked to point to the best place to feel safe from the lion. In Experiment 2, 3- to 5-year-old Israeli, Japanese, and American children were asked to point to 1 of 4 tree silhouettes (Australian Pine, African Fever Tree, and 2 African Umbrella Thorns). Children were asked to point to the prettiest tree and best tree for various refuge attributes, including feeling safe from a lion. Choice of the prettiest tree was examined because adults from several countries prefer trees with wide crowns, a property that might characterize habitat quality as proffered by the savanna hypothesis. The same silhouettes were used in Experiment 3 to examine 3- to 4-year-old American children, adding questions about the best tree for shade and best location in the canopy of each tree to feel safe from the lion. Results suggestive of relic sexual dinichism were most apparent in the first and third experiments, in which girls selected the acacia tree in a significantly greater proportion than the crevice and top of boulder, and 4-year-old girls selected refuge sites significantly closer to the crown edges than boys did for the widest crowned acacias. About half of the children selected the Australian Pine as the prettiest tree, a finding that does not support the aesthetic component of the savanna hypothesis.