It's a very, very sexually differentiated pattern of play. Watching at 10-second clips, researchers recorded more than 20,000 observations of the children, examining their play partners and activities. Just three of the study's 28 boys played with girls more than boys. Generally, the boys' play displayed predictable characteristics, Martin says. The boys will kind of go up with a little bit of teasing and taunting, 'come chase me,' and run off, and then another little boy will follow.
Girls are even more gender-specific.
About 90 percent of girls play with girls more than boys, and 45 percent of these play with girls 90 percent of the time. Only one of the 33 girls played more with boys. They play close to teachers, she says. They could be doing art, dressing up. As the observers watched over the course of the six months, children increasingly played with their own gender, Martin says.