A Developmental-Genetic Analysis of Common Fears from Early Adolescence to Early Adulthood

Abstract

A 51-item fear survey was administered to more than 2,600 adolescents and adults, including m ore than 400 pairs of like-sex twins, to examine developmental patterns and genetic influences on common fears. Raw data were age-sex standardized and subjected to factor analysis, and preliminary analyses of the factor scores documented both age and genetic effects. Some fears habituate with age; others exhibit sensitization; and, for some fears, intensity is uniform across development. Genetic effects were found for all factors, but the magnitude of such effects varied. Based on these initial analyses, developmental patterns of genetic and environmental influences on self-assessed fears were examined in 354 pairs of like-sex twins, ages 14-34. Hierarchical multiple regression was used to predict a twin's fearfulness from the co-twin's fear, the age and zygosity of the twin pair, and the interactions of these 3 predictors. For all fear factors, co-twin's score and the interaction of co-twin's score with pair zygosity significantly contributed to the prediction of a twin's fearfulness, but the magnitude of both effects varied for different fears. For 2 fear factors, Personal Death and Loved One's Misfortunes, 3-way interactions of co-twin's score, age, and zygosity were observed. The findings suggest significant genetic modulation of developmental patterns in the acquisition and maintenance of some adaptive fears.

Heritability and Prevalence of Specific Fears and Phobias in Childhood

“…These results harmonize well with the only previous study on fears in children, which report heritabilities for fears of the unknown at .46, for fears of injury and small animals at .46, for fears of danger at .34, and for a total fear score at .29 (Stevenson et al, 1992). Studies on adults also give firm evidence that liability to phobias and fears is in part genetic (Rose & Ditto, 1983 ;Rose et al, 1981 ;Simonoff et al, 1997 ;Stevenson et al, 1992 ;Torgersen, 1979).…”

“…Twin studies can be used to disentangle genetic and environmental contributions of a particular phenotype. Such studies have indicated that fears and phobias show considerable genetic influence in adults (Kendler, Neale, Kessler, Heath, & Eaves, 1992 ;Phillips, Fulker, & Rose, 1987 ;Rose & Ditto, 1983 ;Rose, Miller, Pogue-Geile, & Cardwell, 1981 ;Torgersen, 1979) and in children (Stevenson, Batten, & Cherner, 1992). However, most studies have been conducted on adults, and because the importance of genetic and environmental influences may vary over age more studies on children are needed.…”

Emotional reactions in children: Verbal, physiological, and behavioral responses to affective pictures

“…Taken together, these data support the hypothesis that gender differences are stable across the lifespan, at least from the age of 7, and are consistent with other evidence that females are more fearful than males across the lifespañ Kagan, 1994;Rose & Ditto, 1983! and across cultures~Ollendick, Yang, Dong, Xia, & Lin, 1995!.…”

Fear-related predictors of vasovagal symptoms during blood donation: it’s in the blood

“…It may be interesting to note that the Medical Fears Survey is a descendant of the traditional Fear Survey Schedule and using data from a large twin sample, we previously observed evidence of significant heritability in most fears on the questionnaire but especially those related to injury and death (Rose & Ditto, 1983). This idea is not originalthis paper included a reference to Hall, (1897) conclusion that ''there is a peculiar prepotent quality about some of these fears that suggests some such ancient origin'' (p. 245).…”