In a study of 175 participants, Segal and Ream (1998) found that monozygotic (MZ) twins reported less decline in grief intensity following the loss of a co-twin, and that twins reported more intense and lasting grief for deceased co-twins than for other relationships. The hypothesis that female twins would report less decline in grief intensity than male twins was not supported. We re-evaluated and expanded upon these results by analyzing a larger sample of twin survivors (n = 423), informed by concepts from evolutionary psychological theory. MZ twins reported significantly higher grief at both retrospective and current time points, but the difference in the slope of decrease in grief between these groups was not statistically significant. We found a similar result when comparing participant sex, with female respondents reporting significantly higher grief at retrospective and current time points; however, sex differences in grief decline over time were not statistically significant. The present findings support the previous authors' third hypothesis that twins grieve longer and more intensely for the death of a cotwin than for other relationships, evidence of the strong social bond that is variously unique to MZ and DZ twin pairs.

在对175名参与者的研究中，西格尔和雷姆（Segal and Ream（1998））发现，单卵双胞胎（MZ）的双胞胎丧失后，其悲伤强度下降的幅度较小，而双胞胎对已故双胞胎的悲伤和悲伤程度比双胞胎高。对于其他关系。女性双胞胎的悲痛强度下降幅度小于男性双胞胎的假设不受支持。我们通过分析更大的双生还者样本（n = 423），并以进化心理学理论中的概念为依据。MZ双胞胎在回顾性和当前时间点均报告有更高的悲伤感，但这些组之间悲伤感下降斜率的差异在统计学上并不显着。在比较参与者的性别时，我们发现了类似的结果，女性受访者在回顾和当前时间点的悲伤程度明显更高；然而，随着时间的流逝，悲伤下降的性别差异在统计学上并不显着。本研究结果支持了先前作者的第三个假设，即双胞胎对苏格兰人的死亡比对其他人的关系更为痛苦，而且更为强烈，这证明了MZ和DZ双胞胎对独特的牢固的社会联系。