This paper analyzes data from the household registers for two villages in the Nôbi region of central Japan in the late Edo period (1717-1869) to assess how grandparents may have affected reproductive strategizing in stem families. The particulars of the family system fostered a culturally favored set of reproductive goals, in particular, a daughter as eldest child, followed by a son (and heir), coupled with gender alternation in subsequent reproduction and overall gender balance.
This reproductive strategy was generally followed during the stem phase of the domestic cycle, when one or both grandparents were present, especially when the family head was in the senior generation. By contrast, a son-first strategy was favored when childbearing began in the conjugal phase of the cycle. This suggests grandparental influence on the junior couple’s reproductive decisions in favor of the cultural ideal. I find that the senior couple’s decision to marry the heir early or late strongly affects the reproductive strategies followed by him after marriage.
I show that when a grandmother is present at the onset of childbearing, especially if she is relatively young, the junior couple ends up with more offspring on average. A controlled analysis of infanticiding behavior is interpreted in terms of conjugal power and coalition formation. It appears that a grandmother gets her way only when she and her son gang up on the daughter-in-law, but such a coalition is likely only when her son dominates the conjugal relationship (which in turn reflects the grandmother’s success in binding the son tightly to her emotionally and in delaying his marriage). Otherwise, the grandmother may be shut out from reproductive decision-making by the solidary conjugal coalition.