Human handedness and scalp hair whorl direction: no evidence for a common cause.
A much wider variation in many physical and cognitive behaviours exists among left-handers than among right-handers, which is evidence for more than one aetiology of left-handedness. Despite these findings some researchers are still attempting to link left-handedness to a single cause, most recently genetic determination, by pairing left-handedness with a presumed genetically based characteristic. One of these characteristics is scalp hair whorl, which may be clockwise, counter-clockwise (purportedly associated with left-handedness), or a reversal whorl (rare). Results of recent research in this topic are reviewed, our own findings are presented, and we conclude that there is no logical reason for, nor evidence of, a common aetiology of both hair whorl direction and handedness.
Perelle
Ira B
IB
Mercy College, Dobbs Ferry, NY 10522, USA. IBP1@AOL.COM
Ehrman
Lee
L
Chanza
Melissa
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003625:Data Collection; D005260:Female; D007839:Functional Laterality / Q000235:genetics*; D006197:Hair / Q000254:growth & development*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012535:Scalp / Q000502:physiology*; D055815:Young Adult