Why do girls throw like girls and boys like boys?

Matt:

I've been watching a lot of kids play baseball this summer, and I've been wondering why most girls throw like girls, while very few boys do. Are girls' arm muscles different? Does it have to do with upper-body strength? Even when girls get into their teens, they still throw like girls. There must be an explanation.

-- Coach, El Cajon

Time out, Coach. We've got a little too much generalizing here. All kids under the age of six or seven tend to "throw like girls" -- rare back with the ball over their shoulders and fling it, sort of like a modified shot-put. Even a baby will use this throwing motion. It's a natural gesture for any untrained kid. But you've got to admit that a woman who practices as hard as a man can develop what might be called a "professional" throwing arm. Boys do; there's no physiological reason a girl can't. It's just that in general, most girls don't particularly want to.

Don't take my word for it. There have been plenty of studies of boys' and girls' athletic development. Several of them have attempted to explain this "you throw like a girl" thing. In one of the better-known investigations, boys and girls were asked to throw a softball with their dominant and then with their nondominant hands. Surprisingly, at almost any age, when they throw with their nondominant hands, boys achieve only slightly better scores than girls. And boys, no matter how well they throw with their dominant hands, tend to "throw like a girl" with the nondominant. Physiologists conclude that boys' better performance is based partly on greater upper-body strength, but mostly on practice. Boys are encouraged to develop their throwing skills, girls aren't.