A University of Rochester pilot-study reveals exposure of two common phthalates (chemicals found in plastics) while in the womb can be linked to boys playing with more girly toys in preschool, read a press release today. The study only looked at 145 preschool children, but the press release reads that "when the concentrations of two common phthalates in mothers’ prenatal urine are elevated their sons are less likely to play with male-typical toys and games, such as trucks and play fighting."