The study -- conducted by scientists at the University of Texas at Austin, the University of Pennsylvania and Michigan State University -- found high school girls, more than boys, look to their close friends when they make decisions such as whether to take math courses and what math classes to take.

Researchers questioned 6,547 high-school girls and boys who had a variety of relationships with peers and tracked the math courses they took. The researchers found all teenage girls, as well as boys with close friends and other peers who made good grades, took more higher-level math than other teenagers. But the connection between those relationships and the math classes was stronger for girls than for boys.

In the end, the researchers found social factors meant more for girls than for boys in decisions about math coursework, especially when enrollment in math classes was optional and when girls were doing well in school.

The findings appear in the journal Child Development.