Today I ran across this Time article that describes how researchers have bred mice to be jocks. Heredity seems to explain 50% of the difference in the observed activity levels. This suggests a similar genetic basis in humans. I’d be curious to find out whether the less active mice also show increased interest in reading, math, and music.
The article naturally addresses the question of whether such genetic factors can be countered:
And maybe one day, [the researcher] speculates, there might even be a drug to compensate for what your genes won’t give you. A drug that makes you want to exercise? Now that’s a pill worth swallowing.
Don’t we already have several of these? I think one is called ephedrine.