- NEW YORK (Reuters
Health) - When it comes to relationships, perhaps absence does make the
heart grow fonder. According to researchers, the less time a man spends
with his female partner after having sex, the more attractive he finds
her--and the greater his interest in having sex with her again. This phenomenon
may arise from an evolutionary strategy known as ''sperm competition,''
according to Todd K. Shackelford, an assistant professor of psychology
in the College of Liberal Arts at Florida Atlantic University.
- ``The bottom line here is that we find (this) effect
for men but not for women,'' he said. Shackelford and his colleagues presented
the findings at the 107th Annual Convention of the American Psychological
Association, held earlier this month in Miami.
- While the investigators have since expanded their study
to include over 2,000 subjects, the initial data was based on assessing
the behavior of 304 German and American heterosexual men between 17 and
71 years of age. All the men were in committed sexual relationships lasting
anywhere from 1 month to 38 years.
- The researchers presented the subjects with a questionnaire,
in which they were asked how many hours had passed since their last intercourse
with their partner, how many hours they had spent with their partner since
last intercourse, and feelings of attraction towards their partner.
- The team found that the less time the men spent with
their partner in the interval since their last encounter, the more attractive
he found her and the greater his interest in sex. Shackelford and colleagues
conclude that it is not simply a question of sexual frustration or a pent-up
drive for sex that motivates the man's urges and feelings of attraction
since their last encounter. In fact, the authors note that a man's urge
to have sex again with his specific partner is independent of the actual
amount of time itself that has passed since their last intercourse. Instead,
it is a function of the amount of time spent with her since they last had
- Shackelford's team believes this behavior may be rooted
in a biological concept called ``sperm competition.'' Studied for over
30 years among birds, insects and nonhuman primates, this evolutionary
theory poses that sperm competition occurs when the sperm of two or more
males simultaneously occupy the reproductive tract of the female and must
compete to fertilize the egg.
- In practical terms, this means that the degree to which
a man wants to have sex with his partner may be a function of how long
he has been away from her since they last had sex. This ''away time'' thus
becomes a period during which he is unable to ensure that she hasn't been
engaging in sex with other men, and putting his reproductive role in jeopardy.
- Shackelford noted that prior research has demonstrated
that sperm counts are higher in ejaculate the longer a man is apart from
his female partner--with sperm count leaping from 350 million when the
man has been with the woman 100% of the time to 800 million when he has
only seen her 5% of the time.
- In an interview with Reuters Health, Shackelford said
that he was focusing on the potential psychological factors associated
with sperm competition.
- ``Behavior doesn't just happen,'' he added. He believes
that sexual attraction is, in part, an evolutionary response to uncertainty
about reproductive status.
- ``It's virtually impossible to guard one's partner 100%
of the time,'' he said. ``So the idea is there's always some risk, because
over human evolutionary history, until very recently, men could never be
certain 100% of the time that the women's offspring is their own.''
Site Served by TheHostPros