Sex-related preferences for real and doll faces versus real and toy objects in young infants and adults.

Findings of previous studies demonstrate sex-related preferences for toys in 6-month-old infants; boys prefer nonsocial or mechanical toys such as cars, whereas girls prefer social toys such as dolls. Here, we explored the innate versus learned nature of this sex-related preferences using multiple pictures of doll and real faces (of men and women) as well as pictures of toy and real objects (cars and stoves). In total, 48 4- and 5-month-old infants (24 girls and 24 boys) and 48 young adults (24 women and 24 men) saw six trials of all relevant pairs of faces and objects, with each trial containing a different exemplar of a stimulus type. The infant results showed no sex-related preferences; infants preferred faces of men and women regardless of whether they were real or doll faces. Similarly, adults did not show sex-related preferences for social versus nonsocial stimuli, but unlike infants they preferred faces of the opposite sex over objects. These results challenge claims of an innate basis for sex-related preferences for toy real stimuli and suggest that sex-related preferences result from maturational and social development that continues into adulthood.