Left Handedness is Important...Maybe

I've been reading an interesting study done by Ian Christopher McManus of the University College London and his colleagues.

According to McManus,"Left-handedness is important because more than 10 percent of people have their brains organized in a qualitatively different way to other people.That has to be interesting.

 When the rate of a [variable trait] changes, then there have to be causes, and they are interesting as well."

Well, probably more interesting to someone who is left handed than others but here is the bit that caught my attention.

 About 11% percent of the population right now is left handed. In 1900 only 3% of the people born were left handed. To investigate the decline in left handedness during the Victorian period the research team looked at a series of news reel type films made between 1897 and 1913 by early filmmakers Sagar Mitchell and James Kenyon.

They counted the number of arm-wavers and then compared the number of left hand wavers to right hand wavers in these early films to a modern control group. They got the control group by searching for "waving" with Google Images. What a hoot! It is so simple and clever.

 I bet the guy who thought of it was left handed. By the way, about 15 percent of the people in the old films waved with their left hand, compared to 24 percent of left arm wavers in the Google search.