FRIDAY, Feb. 25 (HealthDay News) -- A fresh look at 19th century
Mormon marriage has found that the more wives to a family, the
fewer offspring any one wife produced.
"Although it's great in terms of number of [overall] children . . . the data show that for every new woman added to a male's household, the number each wife produced goes down by one child or so," study author and evolutionary biologist Michael Wade, from Indiana University in Bloomington, said in a university news release.
To arrive at this conclusion, Wade and his colleagues reviewed
the detailed records kept by the Utah Population Database regarding
the births, marriages and deaths of 186,000 adults and 630,000
children who lived there between 1830 and 1894.
During that time-frame, marriages based on a system of a single
husband and multiple so-called "sister-wives" began to be phased
out in response to internal social shifts within the Mormon church,
as well as new federal legislation banning the practice, the study
In addition to the primary finding, the investigators also found
support for a long-standing notion that polygamy isn't a
universally good deal for all men, dividing them into haves (those
with many wives) and have-not's (those with none).
"When the ratio of sexes is about equal, for every male that has three mates, there must be two males that have none," Wade said. "If a male has even more mates, then the disparity among male 'reproductive' haves and have-not's can become quite great."
In the world of 19th-century Mormon families, this meant that as
polygamy fell to the wayside, the reproductive playing field evened
out with an increasingly broader group of Mormon men experiencing
both mating and reproductive "success," according to the report in
the March issue of
Evolution and Human Behavior.
The research was funded by the U.S. National Institutes of
Health and the National Science Foundation.
The University of Utah has more at their
Genetic Science Learning Center.