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A Twin Study of Attachment in Preschool Children
Author(s) -
O'Connor Thomas G.,
Croft Carla M.
Publication year - 2001
Publication title -
child development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.103
H-Index - 257
eISSN - 1467-8624
pISSN - 0009-3920
DOI - 10.1111/1467-8624.00362
Subject(s) - concordance , dizygotic twins , psychology , developmental psychology , twin study , dizygotic twin , similarity (geometry) , monozygotic twin , sibling , degree (music) , heritability , genetics , biology , medicine , physics , artificial intelligence , obstetrics , computer science , acoustics , image (mathematics)
The degree to which individual differences in child – parent attachment were mediated by genetic, shared environmental, and nonshared environmental influences was investigated. One hundred and ten preschool‐aged twin pairs ( N = 220) were assessed in the Strange Situation and coded using conventional four‐way classifications and a continuous measure of attachment security. The degree of sibling similarity in attachment was substantial, with an overall concordance rate of 67% at the secure/insecure level. The degree of concordance was equally high in monozygotic and dizygotic twin pairs, 70% and 64%, respectively, suggesting little genetic influence but a moderate degree of discordance. Twin similarity on the continuous measure of attachment security was r (57 ) = .48 and r (53 ) = .38 for monozygotic and dizygotic twin pairs, respectively, also consistent with a modest role for genetic influence but a significant effect for shared and nonshared environment. The implications for genetic influences on the environment and for understanding nonshared and shared environmental influences are discussed.