TY  - JOUR
PY  - 1976//
TI  - Twins: within-pair similarity on Bayley's Infant Behavior Record
JO  - Journal of genetic psychology
A1  - Matheny, A. P.
A1  - Dolan, A. B.
A1  - Wilson, R. S.
SP  - 263
EP  - 270
VL  - 128
IS  - 2d Half
N2  - 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>
LA  - en
SN  - 0022-1325
UR  - http://dx.doi.org/
ID  - ref1
ER  -