“There’s nothing hardwired in our brains that says pink is for girls and blue is for boys,” says Lise Eliot, a neuroscientist at the Chicago Medical School at Rosalind Frank University and author of Pink Brain, Blue Brain: How Small Differences Grow Into Troublesome Gaps—and What We Can Do About It. It’s purely a cultural phenomenon. By the time children are toddlers, Eliot says, boys start rejecting pink because they realize it may diverge from what’s expected. 

These apparel choices can have enduring repercussions by affecting kids’ interests and long-term goals. For instance, since most female clothes are more fitted, they often double as restraints, Eliot says, pushing girls away from physical activities. Kids’ play habits matter, because they affect development and ultimately, even what career they end up embracing. If a girl is tugged away from liking outer space by societal pressures, she probably won’t veer toward an aerospace profession later in life. If a boy is discouraged from playing with dolls and wearing bold clothes, they may not want to get into fashion design one day. “They see it’s the boys with the rocket ships and the girls with the pretty flowers,” adds Eliot.

At major retail outlets such as Children’s Place and Gymboree, there are few, if any, options for the girl who loves dinosaurs or football. Same goes for the boy who loves unicorns and hearts.