People Often Claim That Girls Are More Socially Aggressive Than

People often claim that girls are more socially aggressive than boys. What does the text say about this claim?

A) It is probably just a stereotype; boys are socially aggressive as often as girls.
B) It is supported by research from countries in North America and Europe.
C) It is supported by research in the U.S., but not in other countries.
D) Boys and girls are equally socially aggressive until about age 9, when girls become much more socially aggressive.