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The research, published by Cell Press
in the April issue of the journal Trends in Ecology and Evolution,
suggests that human mating strategies are not likely to conform to a
single universal pattern and provides important insights that may impact
future investigations of human mating behaviors.
In 1948, Angus J. Bateman's performed some now famous
studies in fruit flies that showed that males exhibit greater variance
in mating success (the number of sexual partners) and in reproductive
success (the number of offspring) when compared to females. In addition,
Bateman demonstrated that there was a stronger relationship between
reproductive success and mating success in males than females.
Bateman concluded that, because a single egg is more
costly to produce than a single sperm, the number of offspring produced
by a female fruit fly was mainly limited by her ability to produce eggs,
while a male's reproductive success was limited by the number of females
he inseminated. These studies supported the conventional assumption that
male animals are competitive and promiscuous while female animals are
non-competitive and choosy.
"The conventional view of promiscuous,
undiscriminating males and coy, choosy females has also been applied to
our own species," says lead study author Dr. Gillian R. Brown from the
School of Psychology at the University of St. Andrews. "We sought to
make a comprehensive review of sexual selection theory and examine data
on mating behavior and reproductive success in current human populations
in order to further our understanding of human sex roles."
Dr. Brown and colleagues examined the general
universal applicability of Bateman's principles. To test one of
Bateman's assumptions, they collated data on the variance in male and
female reproductive success in 18 human populations. While male
reproductive success varied more than female reproductive success
overall, huge variability was found between populations; for instance,
in monogamous societies, variances in male and female reproductive
success were very similar.
The researchers also examined factors that might
explain variations across human populations that are not in keeping with
the prediction of universal sex roles. "Recent advances in evolutionary
theory suggest that factors such as sex-biased mortality, sex-ratio,
population density and variation in mate quality, are likely to impact
mating behavior in humans," concludes Dr. Brown. "The insights gained
from this new perspective will have important implications for how we
conceive of male and female sexual behavior." |
