Van Hulle C A, Corley R, Zahn-Waxler C, Kagan J, Hewitt J K
Institute for Behavioral Genetics, University of Colorado, Boulder 80309-0447, USA.
Twin Res. 2000 Dec;3(4):259-65. doi: 10.1375/136905200320565238.
Heart rate was recorded on 210 MZ and 174 DZ same sex twin pairs participating in the MacArthur Longitudinal Twin Study (MALTS) at age 14, 20, 24, 36 months and 7 years. Heart rate was monitored in the laboratory at all ages. At ages 14 to 36 months, heart rate was monitored prior to a set of cognitive tasks. At age 7 years heart rate was recorded during a mood-eliciting videotaped presentation. At this age only heart rate monitored during neutral portions of the presentation were used. Mean heart rate declines substantially across this age range, but is similar in boys and girls and for MZ and DZ twins at each age. Heart rate is moderately correlated across all time points suggesting that individual differences in heart rate are relatively stable over this age range. Multivariate genetic and environmental models were fitted to the raw data. In general, genetic factors contribute to the stability of individual differences over time. Shared and non-shared environment factors tended to be occasion specific, with non-shared environment contributing substantially to the individual variation at each age. Shared environment and non-shared environment also contributed a modicum to the stability across time. Thus, individual differences in resting heart rate is a relatively stable, heritable trait from infancy to early childhood.
在参与麦克阿瑟纵向双胞胎研究（MALTS）的210对同卵（MZ）和174对异卵（DZ）同性双胞胎中，记录了他们在14个月、20个月、24个月、36个月和7岁时的心率。所有年龄段的心率均在实验室中进行监测。在14至36个月大时，在一组认知任务之前监测心率。在7岁时，在一段引发情绪的录像展示过程中记录心率。在这个年龄段，仅使用展示过程中性部分所监测到的心率。在这个年龄范围内，平均心率大幅下降，但在各年龄段，男孩和女孩以及同卵和异卵双胞胎的心率相似。心率在所有时间点之间存在中度相关性，这表明在这个年龄范围内，个体心率差异相对稳定。对原始数据拟合了多变量遗传和环境模型。一般来说，遗传因素有助于个体差异随时间的稳定性。共享环境和非共享环境因素往往具有特定场合性，非共享环境在每个年龄段对个体差异有很大贡献。共享环境和非共享环境对随时间的稳定性也有一定贡献。因此，静息心率的个体差异是从婴儿期到幼儿期相对稳定的可遗传特征。
