The Genetic Factor in Autonomic Nervous System Function

Measurements of vaso-motor persistence time, palmar standing skin resistance, reclining pulse pressure, salivation, respiration rate, reclining volar conductance, “heart period” and “autonomic balance” have been made during three different years upon a group of children between 6 and 12 years of age. The group contained many pairs of siblings and six pairs of monozygotic twins. Comparison of the measures of siblings with those of twins shows them to be less alike than those of the twins. Similar comparisons show the unrelated less alike than the siblings and the unrelated less alike than the twins. Most of the differences are statistically significant. Correlations of the scores of pairs of twins, pairs of siblings and matched unrelated children show the correlations for the twins highest, siblings next and unrelated least. These results suggest that what one might call “autonomic constitution” may be at least partially an inherited characteristic. These findings should help to explain the genetic predisposition to many of the psychosomatic diseases.