Nature vs Nurture becomes especially interesting when the subjects are too young for life experience to play a large role. Babies aged 4 to 8 months have had almost no cultural training, yet the boys gaze at the truck more often and the girls gaze at the doll more often in a controlled toy-preference test. Because the toy positions are swapped each round to prevent bias, the pattern suggests that some preferences may come from birth rather than from life experience.