Sex differences in variance of intelligence across childhood

TY - JOUR

T1 - Sex differences in variance of intelligence across childhood

AU - Arden, R

AU - Plomin, R

PY - 2006/7

Y1 - 2006/7

N2 - Why are males over-represented at the upper extremes of intelligence? One possibility for which there is some empirical support is that variance is greater among adult males. There is little published evidence of the development of that variability - is it manifest in early childhood or does it develop later? We explored sex differences in phenotypic variance in scores on a general ability factor extracted from several tests of verbal and non-verbal ability at ages 2, 3, 4, 7, 9 and 10 (Ns from > 10,000 to > 2000) in a sample of British children. We found greater variance, by Levene's test of homogeneity of variance, among boys at every age except age two despite the girls' mean advantage from ages two to seven. Girls are significantly over-represented, as measured by chi-square tests, at the high tail and boys at the low tail at ages 2, 3 and 4. By age 10 the boys have a higher mean, greater variance and are over-represented in the high tail. Sex differences in variance emerge early - even before pre-school - suggesting that they are not determined by educational influences. (c) 2006 Elsevier Ltd. All rights reserved

AB - Why are males over-represented at the upper extremes of intelligence? One possibility for which there is some empirical support is that variance is greater among adult males. There is little published evidence of the development of that variability - is it manifest in early childhood or does it develop later? We explored sex differences in phenotypic variance in scores on a general ability factor extracted from several tests of verbal and non-verbal ability at ages 2, 3, 4, 7, 9 and 10 (Ns from > 10,000 to > 2000) in a sample of British children. We found greater variance, by Levene's test of homogeneity of variance, among boys at every age except age two despite the girls' mean advantage from ages two to seven. Girls are significantly over-represented, as measured by chi-square tests, at the high tail and boys at the low tail at ages 2, 3 and 4. By age 10 the boys have a higher mean, greater variance and are over-represented in the high tail. Sex differences in variance emerge early - even before pre-school - suggesting that they are not determined by educational influences. (c) 2006 Elsevier Ltd. All rights reserved

U2 - 10.1016/j.paid.2005.11.027

DO - 10.1016/j.paid.2005.11.027

M3 - Article

VL - 41

SP - 39

EP - 48

JO - Personality and Individual Differences

JF - Personality and Individual Differences

IS - 1

ER -