Birth order and hand preference in chimpanzees (Pan troglodytes): implications for pathological models of handedness in humans.
The effect of birth order on hand preference was assessed in a sample of 154 captive-born chimpanzees. Subjects were classified as first, middle, or latter born using 2 classification criteria based on their birth order. Hand preference was measured using a task that elicited coordinated bimanual actions. Significant birth-order effects were found for both classification criteria, with first- and latter-born subjects exhibiting a lesser degree of right-handedness compared with middle-born subjects. These data suggest that biological rather than sociological factors play a greater role in explaining the observed birth-order effects on hand preference in humans.
Hopkins
W D
WD
Department of Psychology, Berry College, USA. whopkins@berry.edu
Dahl
J F
JF
D000704:Analysis of Variance; D000818:Animals; D001722:Birth Order; D004292:Dominance, Cerebral; D005260:Female; D007839:Functional Laterality; D008297:Male; D008423:Maternal Age; D008954:Models, Biological; D002679:Pan troglodytes / Q000502:physiology*; D010298:Parity; D011597:Psychomotor Performance