祖辈投资的个体差异:进化心理学的视角

Individual Differences in Grandparental Investment:An Evolutionary Psychological Perspective

作为亲代投资的扩展,无论在传统社会还是在现代社会,祖辈投资对于青少年的健康发展和社会适应都有重要的意义。不过,不同祖辈对于孙辈的投资程度存在普遍而稳定的个体差异,母系祖辈投资多于父系祖辈,女性祖辈投资多于男性祖辈。这一经典模式符合进化心理学中父性身份不确定性假设和特定性别繁衍策略假设。目前没有可靠证据表明祖辈投资受孙辈性别的影响,这意味着性染色体相关度假设没有得到明确支持。包括祖辈居住距离和父权文化在内的许多因素都会影响祖辈投资的表现。未来祖辈投资个体差异方面的研究,可以从代际冲突的视角进行,明确检验孙辈性别和亲缘线索的影响。

Grandparenting which is an important part of human children has been practiced in both traditional alloparenting for the prolonged development of and modern societies. We review the relevant evolutionary psychology literature to highlight some of the characteristics of human grandparenting. Among some of the well observed characteristics are the lineage differences in grandparenting. Specifically, maternal grandparents seem to invest more than paternal grandparents, and female grandparents seem to invest more than male grandparents. This observation is in line with the paternity uncertainty hypothesis whereby paternal parenting is regulated by paternity doubt a male parent has over his offspring. Less widely observed are emerging evidence suggesting grandparental investment differences due to the grandchild＇s sex This observation is explained by the sex-chromosome hypothesis in that a woman is least related to her paternal grandson, equally related to her maternal grandson and granddaughter, and most related to her paternal granddaughter. Other variables such as residential proximity and patrilocality may also shape the grandparental investment. Future studies should take the intergenerational conflict perspective to investigate inclusive fitness of grandparents and their grandchildren.