Household with mother(-in-law) means fewer kids

Women who live with their own mother or their mother in law in the same household have, on average, fewer children than women who only live with their spouse. Martin Fieder and colleagues, evolutionary anthropologists from the University of Vienna, report this on the basis of intercultural data of 2.5 million women worldwide. Until now, evolutionary biologists have assumed the opposite. The study appears in the renowned scientific journal "Royal Society Open Science".

Until now evolutionary biologists have assumed that the presence of a woman’s mother or her mother in law in the household increases the woman’s number of children and, thus, the grandmother’s number of grandchildren. Furthermore, it was assumed that women frequently move to the families and households of their husbands.
By analyzing the records of more than 2.5 million women from 14 countries worldwide, Martin Fieder and his colleagues from the Department of Anthropology of the University of Vienna found that in most cases, women do not live with either their own or their mother in law in the same household, and if they do, they have on average fewer children compared to women who only live with their spouse.

The authors suppose that two reasons may have contributed to their results: reproductive competition and competition on resources with their daughters. Particularly the latter is plausible as the analyses included many developing countries. But also reproductive competition is reasonable as a mother/mother in law in the household is particularly negatively associated with a woman’s number of children if she is still in her reproductive years: a younger grandmother may have children on her own which is more important than raising her grandchildren, hence, they are competing across generations.

Publication in "Royal Society Open Science":
Huber S, Zahourek P, Fieder M.: Living with own or husband’s mother in the household is associated with lower number of children: a cross-cultural analysis. 2017
R. Soc. open sci. 4: 170544.

Wissenschaftlicher Kontakt

Mag. Dr. Martin Fieder

Department für Anthropologie
Universität Wien
1090 - Wien, Althanstraße 14 (UZA I)
+41-1-4277-500 21
+43-664-817 48 39


Mag. Alexandra Frey

Pressebüro und stv. Pressesprecherin
Universität Wien
1010 - Wien, Universitätsring 1
+43-1-4277-175 33
+43-664-60277-175 33