Study finds threats to family predict women’s decisions to volunteer for a paramilitary organization

Women were more likely to volunteer for an all-female paramilitary organization during World War II if they had brothers or husbands who were currently serving in the military, according to new research published in Evolution and Human Behavior.

“I have been interested in human group affiliation, in-groups and the evolutionary logic leading to group formation ever since I was a graduate student at Rutgers studying under my advisor Robert Trivers,” said study author Lynch Robert, a postdoctoral researcher at the University of Turku.

“In my first postdoc at the University of Missouri, I analyzed a database of a previously uncontacted population of Yanomamo Indians in the Amazon rainforest collected by Napoleon Chagnon. While there I did some work on the role of something called cross-cousin marriage (arranged marriages between the children of opposite sex siblings) in maintaining ties and reducing between different groups of Yanaomamo.”

“My interest in coalitions and group identification has continued and when I saw the opportunity to explore the role of kinship (e.g. siblings and spouses) on the willingness of women to sacrifice for their country using a new database from Finland, I took it.”

That database included structured interviews of approximately 250,000 evacuees from Finnish Karelia during World War II. Lynch and his colleagues were particularly interested in 78,117 women in the database — 9,078 of whom were listed as being members of Lotta Svärd, a Finnish auxiliary paramilitary group.

On November 30th, 1939 the Soviet Union invaded Finland, marking the beginning of the Winter War, and the Karelian population fled to western Finland, although approximately 60% of these evacuees returned to Karelia when it was temporarily recaptured by Finland between 1942 and 1944.

Many Karelian women joined the Lotta Svärd organization, which was tasked with supporting troops as nurses, air raid spotters, mess personnel and in other auxiliary capacities.

The researchers found that women who were single and did not have any children when the war began were more likely to volunteer if they had brothers. Their number of sisters, however, had no effect on their likelihood of volunteering for the paramilitary group.

Women who were married when the war began were also more likely to volunteer if their husbands were serving in the military.

“Perhaps the most interesting result is that women may be more likely to identify with a larger group (e.g. their country, a religion, a political organization, ideology, etc) when they perceive that their actual relatives are threatened,” Robert told PsyPost.

“In other words, these results predict that women are more likely to identify with a particular group or cause if they perceive that family members are at risk and this may be a different pathway than those that men typically use to form and identify with groups (e.g. bands of brothers).”

But the study — like all research — includes some limitations.

“This research is preliminary and suggestive only. For example, we really don’t really know why women seem more likely to join this paramilitary organization when they have more brothers or their husbands are serving in the military,” Robert explained.

“Perhaps it is because they perceive risks to male family members but maybe it is something else that we don’t understand or some unknown factor that correlates with military service or having more male siblings. We would need more details on these women to answer this question.”

“Our study really just points to the possible importance of personal relationships and social networks in eliciting feelings of group identity among women,” Robert added.

“Overall, these findings advance our understanding of the conditions under which individuals are more likely to sacrifice for their community and indicate that for women a willingness to sacrifice may rely on something called kin psychology, whereby threats to actual family members can trigger feelings of shared biology with other unrelated individuals in a threatened group.”

The study, “Self sacrifice and kin psychology in war: threats to family predict decisions to volunteer for a women’s paramilitary organization“, was authored by Lynch Robert, Lummaa Virpi, and Loehr John.