Why are some people left-handed? Here’s some research reported in The Independent:
It is known that left-handers tend to suffer more health problems and are at greater risk of serious accidents compared to right-handers. So, all other things being equal, the left-handed trait, which is largely genetic, should have died out long ago in prehistory.
There must, therefore, be some hidden advantage to being left-handed that counteracts the risks, but the problem for biologists was trying to work out what this advantage was.
A pair of researchers from the University of Montpellier (France) find support for a theory that the evolutionary value to being left-handed comes from the advantage of surprise in hand-to-hand combat against right-handed people.
Charlotte Faurie and Michel Raymond compared homicide rates, which includes murders and executions, in eight native societies around the world, from the Inuit of the Arctic to the Yanamamo indians of the Amazon. They found that as this measure of violent aggression increased in each society, so did the proportion of men who are left-handed.
Dr Faurie said: “We have found a direct correlation between the level of violence in a given society and the proportion of left-handers. This indicates that fighting can be an important selection pressure in the evolution of left-handedness.”
A competing researcher was not persuaded, suggesting that greater creativity and other advantages may well account for the persistence of lefties.
I haven’t read the Faurie and Raymond article itself, just the newsreport, but my wife and my youngest son are left-handed…. Well, let’s just say that I find the research very interesting and leave it at that.