DECREASE IN GRIEF INTENSITY FOR DECEASED TWIN AND NONTWIN RELATIVES -AN EVOLUTIONARY PERSPECTIVE

Based on evolutionary reasoning it was hypothesized that: (1) dizygoti c (DZ) twins would show greater reduction in grief intensity than mono zygotic (MZ) twins for their deceased co-twins, (2) female twins would show less reduction in grief intensity than male twins for their dece ased co-twins, and (3) twins would show less reduction in grief intens ity for deceased co-twins than for other deceased relatives. Using a 7 -point scale, 175 bereaved twins assessed their grief intensities as r ecalled 1-2 months after the loss and currently. Decrease in grief int ensity was significantly greater for DZ twins than for MZ twins, as ex pected, although significant gender differences were not found. Partic ipants also evidenced significantly less decrease in grief for decease d co-twins than for other deceased relatives. The implications of thes e findings for an evolutionary theory of bereavement are discussed. (C ) 1998 Published by Elsevier Science Ltd. All rights reserved.