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The removed material spans 02:55, 11 February 2006 to 10:16, 11 March 2006, and was moved from here at 2006-03-11 10:27:30
/* Genetic factors */ deletion due to failed verification
This statement does not correlate with the citations provided.
"Other mechanisms may play a role in handedness, for example hormone signalling. Medland et al. found a CAG repeat length variant in the androgen receptor gene (AR) that is positively correlated with left-handedness in females, and negatively correlated in males. This same variant is positively correlated with testosterone levels in males, and negatively correlated in females." This may help to explain why there are more left-handed men than women (around 12% in men versus 10% in women globally). However, another study has found that this variant is instead associated with mixed-handedness in males (and not left-handedness), conflicting with the original results.
One citation provided is a meta-study, that doesn't give explanation on why "left handedness" is more prevalent in males, just that it is more prevalent in males, the other citation provided states the exact opposite of the above text:
Behav Genet. 2005 Nov;35(6):735-44. Opposite effects of androgen receptor CAG repeat length on increased risk of left-handedness in males and females.
"Likelihood of left handedness increased in those individuals with variants of the androgen receptor associated with lower testosterone levels"
I know this is original research on my part, which is why I'm only putting it in talk -- but why is the possibility ignored that the correlation between parents and children might be environmental rather than genetic? You know, the nature vs nurture thing? To say "if both parents of a child are left-handed, there is a 26% chance of that child being left-handed", as if it supports the genetic theory, is a gigantic logical leap. If a kid's raised in a house where both parents demonstrate how to do things with their left hands, and goes on to use her right hand with 74% likelihood, isn't that an amazing demonstration of how little Nature (genetics) OR Nurture (environmental factors) has to do with it?
If there's evidence that suggests that it's nature rather than nurture, I think that evidence should be presented in this article. --RobertStar20 (talk) 15:13, 17 July 2014 (UTC)