Rebecca's team had a pretty concrete goal: figure out if male and female preferences were genetically hardwired based on sex.
Researchers had parents sit at a table with their child that had a doll and a truck on it. Moms and dads were then instructed to play with their kiddos using one of the toys, while discourageing the use of another one.
"Infants' preferences for the toys used in the study were not altered by a few minutes of their parents encourageing them to play with a certain toy," said Woods. "These short-term encouragements did not affect their preferences."