Matheny A P, Dolan A B, Wilson R S
J Genet Psychol. 1976 Jun;128(2d Half):263-70. doi: 10.1080/00221325.1976.10533996.
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.
对参与一项纵向研究的同性双胞胎，通过对贝利婴儿行为记录上的行为评分进行汇总，得出汇总分数。第一年的分数基于在3、6、9和12个月时进行的访视，涉及55对同卵双胞胎和27对异卵双胞胎；第二年的分数基于在18、24和30个月时进行的访视，涉及47对同卵双胞胎和27对异卵双胞胎。在第一年，几乎所有行为的同对内相关性，同卵双胞胎都比异卵双胞胎更强；在第二年，除了更多认知行为外，同卵双胞胎的同对内相关性与异卵双胞胎相似。计算了两个行为集群的综合分数——一个由与初级认知相关的行为组成，另一个由与外向性相关的行为组成。在第一年和第二年，同卵双胞胎的同对内相关性都高于异卵双胞胎，表明对更多认知行为的遗传影响更强且更一致。
