There's a memorable scene in the 1993 movie Sandlot in which two rival baseball clubs engage in a tense war of words over which team is superior. After a few exchanges, Ham Porter of the ragtag Sandlot crew ends the battle with perhaps the most memorable line of the film: "You play ball like a girl!"
It was an insult then, and remains one today. For some reason, women have not developed the throwing mechanisms that would allow them to match their male cohorts. In a Washington Post story, Tamar Haspel examines the origin of this gender gap.
Haspel, who has noticed that her throwing motion is particularly weak, discovered that boys of all ages across the globe tend to throw better than girls.
"The overhand throwing gap, beginning at 4 years of age, is three times the difference of any other motor task, and it just gets bigger across age," said Jerry Thomas, dean of the College of Education at the University of North Texas. "By 18, there’s hardly any overlap in the distribution: Nearly every boy by age 15 throws better than the best girl."
Haspel writes that a skillful overhand throw involves three phases: the step, the rotation and the whip. Men are superior at each of those phases, and the difference may be most prevalent in the rotation. Thomas said men tend to rotate their hips forward before turning their shoulders and opening their bodies, whereas women rotate their hips and shoulders in one motion. Women lose speed in their throwing motion by not separating their rotation.
The explanation for this contrast goes back thousands of years. According to Thomas, the men who were best at throwing rocks got the girls. Meanwhile women were often holding a baby when they threw, and that constricted their motion. Now, Haspel notes, many women have a throwing motion that looks more like they are tossing a dart. Harvard softball coach Jenny Allard called overhand throwing "the most undertaught skill in softball."
With the proper teaching, women can overcome the evolutionary head start of men. Indeed, if girls were to learn the proper rotation and throwing motion, they could render Ham Porter's insult useless.
For the full story, see here.