@article{ref1,
title="Twins: within-pair similarity on Bayley's Infant Behavior Record",
journal="Journal of genetic psychology",
year="1976",
author="Matheny, A. P. and Dolan, A. B. and Wilson, R. S.",
volume="128",
number="2d Half",
pages="263-270",
abstract="Summary scores for behaviors rated on Bayley's Infant Behavior Record were obtained by summing sequential ratings for same-sex twins participating in a longitudinal study. The first year scores were based on visits made at 3, 6, 9, and 12 months, by 55 identical and 27 fraternal pairs; the second year scores were based on visits at 18, 24, and 30 months, by 47 identical and 27 fraternal pairs. During the first year, within-pair correlations for almost all behaviors were stronger for identical than for fraternal pairs; in the second year, within-pair correlations for identical twins were similar to those of fraternal twins except for the more cognitive behaviors. Composite scores were calculated for two behavioral clusters--one composed of behaviors related to Primary Cognition, and the other composed of behaviors related to Extraversion. Within-pair correlations were higher for identical than for fraternal twins in both the first and second years, indicating stronger and more consistent genetic influences on the more cognitive behaviors.<p /><p>Language: en</p>",
language="en",
issn="0022-1325",
doi="",
url="http://dx.doi.org/"
}