Accurate throwing and speech require excellent timing, as those who have been unfortunate enough to indulge in energetic spousal debates will know well enough. The same structures in the brain are involved in both of these activities. This is discussed in a recent paper by Zhu and Bingham (1). They point out that just as our speaking abilities make us human, so does our ability to throw things long distances. Indeed, put these two things together and we have the start of an army, or a hunting party at the very least.
We have built in perceptual biases that help us make sense of the baby talk that we hear from admiring adults. The concept proposed by Zhu and Bingham is that we have perceptual biases built in which help us find the right stone to throw at, well, we had better restrict it to prey.
From a very early age we learn to associate size and weight and if we had wanted to knock over our woolly mammoth, we would have chosen a large heavy stick (sharp of course.) This size-weight judgment is so strongly ingrained that we assume bigger things to be heavier, even when they aren’t. Apparently this goes right back to our bias which helps us find the optimal thing to throw.
We learn to throw early, as we learn to talk early. These days we are usually discouraged from indulging this passion too widely. Pitching a baseball or throwing a javelin on the sports field is acceptable, but leaves us with a fairly limited choice and keeps us civilized. There are no such restrictions on our use of speech, though. On occasion, it seems difficult to not use the former in response to the latter.
- Q.Zhu and G.P.Bingham, Evolution & Human Behavior, 32, 288, (2011)
Interesting point here, Jim. I believe most of our politicians are keen to the former (as in hurling insults and false polls).