Sinistral survival

Turns out being left-handed does confer some advantages beyond a quicker path to first base:

http://news.bbc.co.uk/2/hi/science/nature/4831218.stm

That's cool for the snails, but it doesn't really help humans much. It is nice to know, however, the hypothesis that left-handedness decreases lifespan appears to be false. Recent scientific studies in Brazilian, Canadian, Danish, and American populations show no correlation between handedness and lifespan. The Brazilian study, in particular, noted that the observed decrease in left-handedness in the geriatric population is due to negative cultural conditioning, and not mortality. (Martin WL, Freitas MB “Mean mortality among Brazilian left- and right-handers: modification or selective elimination?” Laterality 2002;7(1):31-44.)

Also of gauche interest - did you know that the chirality of your hair whorl predicts handedness? People whose hair twists clockwise are overwhelmingly (94%) right-handed, while those with counterclockwise hair have a 50-50 shot at it (the genetics are complicated - hair chirality is apparently linked to a gene that determines whether handedness is genetically patterned or stochastic – technically called a random-recessive genetic model). Anyway, the publication is: Klar, AJS “Human Handedness and Scalp Hair-Whorl Direction Develop From a Common Genetic Mechanism” Genetics 2003 165: 269–276). Now everyone go stare at the top of your head ;)

For all those lefties in my family, you will be disappointed to know that despite having counterclockwise hair, Bug appears to be right-handed. I wonder if the supposed “lefty” differences in brain physiology (increased interconnectivity and cooperative function between the hemispheres) are genetically linked to the whorl regardless of handedness or if they are also random in the counterclockwise population?