杏吧原创

Why are some people left-handed and others right-handed?

(Continued)

鈥� The replies (6 September 2008) to this question accept the assertion that there is no demonstrable advantage to keeping the genes for left-handedness alive in the population. I suspect that none of your respondents play racket sports.

It is a common tactic in squash and badminton to force your opponent to play a backhand shot because most people are weaker on their backhand than their forehand.

For a left-hander, the handedness is reversed, so shots aimed at where the backhand would normally be turn into easy forehand returns. And because the left-hander is swinging the racket from a different position, they can make different angles on shots than a right-hander would. I have seen many games where players persist in hitting to their usual target areas and being wrong-footed by returns 鈥� admitting afterwards that they hadn鈥檛 even registered that they were playing a left-hander.

Racket sports are not likely to have had much influence on the genetics of handedness in our forebears, but success in both hunting and fighting probably did. Left-handed throwers of weapons could achieve different angles than their right-handed companions and perhaps at least occasionally make a successful kill that a right-hander could not have. Being a left-handed wielder of a knife or sword probably also gave some advantages in combat, as one鈥檚 opponents would have had less practice against your moves.

鈥淩acket sports are unlikely to have influenced the genetics of handedness, but success in fighting probably did鈥�

Kathy Nelson, Reading, Berkshire, UK