Did they record overt threats as opposed to stereotyped? As a little girl competing against boys in spelling bees and other academic competitions, I'm sure that there were stereotyped threats, but I was at the time too young (and too antisocial w/regard to peer group influence and too prideful) to regard them. But actual threats from the boys I competed against managed to be effective to back me down from beating them. Like boxing, there's a huge psychological component, which children may not be wholly prepared to combat.