Children's, Adolescents', and Young Adults' Heart Rate Reactivity to, and Recovery from, a Brief Psychological Stressor

Heart rate reactivity to a 2 minute mental arithmetic stressor delivered under timed and competitive conditions and graded for age-related difficulty was collected on 148 males and 153 females grouped into five age cohorts ranging from 7 to 20 years. Data on resting heart rate, heart rate during the stressor period, and post-stressor recovery showed significant sex (females had higher heart rates) and age effects (there was a general decrease in heart rate with age). There were no significant interactions between age and sex. Mean heart rate reactivity also showed significant variation with age, but no significant differences between males and females, nor any significant interaction between age and sex. The age effect for heart rate reactivity appeared to be a result of the oldest age group having significantly greater increases in heart rate than all other age groups.