Featured Research

from universities, journals, and other organizations

When leaving your wealth to your sister's sons makes sense

Date:
October 16, 2012
Source:
Santa Fe Institute
Summary:
In some human societies, men transfer their wealth to their sister's sons, a practice that puzzles evolutionary biologists. A new study has produced insights into "matrilineal inheritance."

To whom a man's possessions go when he dies is both a matter of cultural norm and evolutionary advantage.

In most human societies, men pass on their worldly goods to their wife's children. But in about 10 percent of societies, men inexplicably transfer their wealth to their sister's sons -- what's called "mother's brother-sister's son" inheritance. A new study on this unusual form of matrilineal inheritance by Santa Fe Institute reseacher Laura Fortunato has produced insights into this practice.

Her findings appear October 17 in the online edition of Proceedings of the Royal Society B.

"Matrilineal inheritance is puzzling for anthropologists because it causes tension for a man caught between his sisters and wife," explains Fortunato, who has used game theory to study mother's brother-sister's son inheritance. "From an evolutionary perspective it's also puzzling because you expect an individual to invest in his closest relatives -- usually the individual's own children."

For decades research on the practice of matrilineal inheritance focused on the probabilities of a man being the biological father of his wife's children -- probabilities that lie on a sliding scale depending on the rate of promiscuity or whether polyandrous marriage (when a woman takes two or more husbands) is practiced.

Of special interest has been the probability value below which man is more closely related to his sister's children than to his wife's children. Below this "paternity threshold" a man is better off investing in his sister's offspring, who are sure to be blood relatives, than his own wife's children.

In her work modeling the evolutionary payoffs of marriage and inheritance strategies, Fortunato looked beyond the paternity threshold to see, among other things, what payoffs there were for men and women in different marital situations -- including polygamy.

"What emerges is quite interesting," says Fortunato. "Where inheritance is matrilineal, a man with multiple wives 'wins' over a man with a single wife." That's because wives have brothers, and those brothers will pass on their wealth to the husband's sons. So more wives means more brothers-in-laws to invest in your sons.

The model also shows an effect for women with multiple husbands. The husband of a woman with multiple husbands is unsure of his paternity, so he may be better off investing in his sister's offspring.

"A woman does not benefit from multiple husbands where inheritance is matrilineal, however," Fortunato explains, "because her husbands will invest in their sisters' kids." Family structure determines how societies handle relatedness and reproduction issues, Fortunato says. Understanding these practices and their evolutionary implications is a prerequisite for a theory of human behavior.


Story Source:

The above story is based on materials provided by Santa Fe Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dr Laura Fortunato. The evolution of matrilineal kinship organization. Proceedings of the Royal Society B, October 17, 2012 DOI: 10.1098/rspb.2012.1926

Cite This Page:

Santa Fe Institute. "When leaving your wealth to your sister's sons makes sense." ScienceDaily. ScienceDaily, 16 October 2012. <www.sciencedaily.com/releases/2012/10/121016162843.htm>.
Santa Fe Institute. (2012, October 16). When leaving your wealth to your sister's sons makes sense. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/10/121016162843.htm
Santa Fe Institute. "When leaving your wealth to your sister's sons makes sense." ScienceDaily. www.sciencedaily.com/releases/2012/10/121016162843.htm (accessed October 21, 2014).

Share This



More Fossils & Ruins News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Newsy (Oct. 19, 2014) A 380-million-year-old fish may be the first creature to have copulative sex - and it was side by side with arms linked, like square dancers. Video provided by Newsy
Powered by NewsLook.com
As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

Newsy (Oct. 19, 2014) With Sweden on the look-out for a suspected Russian sub, a lot of people are talking about the Cold War, but is it an apt comparison? Video provided by Newsy
Powered by NewsLook.com
So, Kangaroos Didn't Always Hop

So, Kangaroos Didn't Always Hop

Newsy (Oct. 16, 2014) Researchers believe an extinct kangaroo species weighed 500 pounds or more and couldn't hop. Video provided by Newsy
Powered by NewsLook.com
1000-Year-Old Viking Treasure Hoard Found in Scotland

1000-Year-Old Viking Treasure Hoard Found in Scotland

Reuters - Light News Video Online (Oct. 14, 2014) A hoard of Viking artifacts dating back over 1,000 years is discovered by a treasure hunter with a metal detector in Scotland. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins