Matriliny as daughter-biased investment

Abstract

From an evolutionary perspective, matriliny presents a puzzle because men in matrilineal societies transmit wealth to their sisters' sons, to whom they are only half as related as to their own sons. It has been argued that such systems would only maximise fitness under unrealistically high levels of paternity uncertainty. In this paper, we propose that matriliny can arise from daughterbiased investment by parents and/or grandparents. We show that daughter-biased investment is adaptive if the marginal benefit of wealth to sons (compared to daughters) does not outweigh the risk of nonpaternity in sons' offspring. We argue that such conditions will be rare where resourceholding polygyny is prevalent but could otherwise be widespread under even moderate levels of paternity uncertainty. The daughter-biased investment model explains two well-known characteristics of matrilineal descent: (a) matriliny's association with high levels of paternity uncertainty and (b) matriliny's ecological correlates, including its association with horticulture, its rarity in pastoralist and agro-pastoralist societies, and the tendency for matriliny to be replaced by sonbiased inheritance during economic development. We present data on wealth, sex, and reproductive success (RS) in two African societies, the matrilineal Chewa in Malawi and patrilineal Gabbra in Kenya, which support the daughter-biased investment theory. D

Community differentiation and kinship among Europe’s first farmers

“…The pattern among the sexes is quite consistent with marriage within a patrilocal kinship system, which is also consistent with independent archaeological (11,43), genetic (6,18,19,48), anthropological (16,(44)(45)(46), and even new linguistic (49) evidence concerning Neolithic Europe. These results have implications for genetic modeling of Neolithic expansion, for which sex-biased mobility patterns and status differences are increasingly seen as crucial (17)(18)(19)40).…”

“…something which is different rather than looking ab initio for a specific postcode of origin" (20). In Discussion and Conclusions, we therefore interpret the 87 Sr/ 86 Sr patterns in context with archeology (2, 3, 13), archaeobotany (11), and cross-cultural anthropology (12,(44)(45)(46), which generally support the premise that "as agricultural input intensifies, rights become more permanent and more exclusive" (13).…”

“…Generally speaking, "male inheritance of land means that males tend to live where they were born, while females marry and move elsewhere" (40). Because patrilocality, intergenerational wealth transfer, and agriculture tend to correlate in small-scale societies (12,13,40,44,46), a simple explanation is that unequal and inherited land access developed in time among the early farmers in Central Europe (cf. ref.…”

Reproductive competition between females in the matrilineal Mosuo of southwestern China

“…The effects that family members have on each other's reproductive success here in the Mosuo may explain why mothers are willing to feed their male offspring, who are not competing for breeding opportunities with any of their other offspring, while females do compete with each other for household resources. While land inheritance could be considered daughter-biased investment, because only daughters can make use of it to raise offspring [27], other investments are male biased if males have relatively light workloads compared with females [5]. Hypotheses for the evolution of menopause are that it reduces reproductive conflict and increases cooperation between generations of human females [18,22,23,[28][29][30].…”

Does Wealth Increase Parental Investment Biases in Child Education?

“…Societies are matrilineal where daughters benefit more from inherited resources than sons, and in such societies girls are likely to be in greater competition with elder sisters for resources, including inherited wealth (e.g. Holden, Sear, andMace 2003, Sear 2008). …”