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BEFORE I got married a few weeks ago, friends told me that flashing a wedding
ring was a sure way to attract female attention. Some said it was because women
consider married men to be safe. Others said a wedding band is a quick way for
women to identify a quality mate, one that鈥檚 been pre-filtered by someone
else.

So in the interests of science, I have been spending more time in bars
lately. As I sip my pint of California microbrew, I keep my left hand clearly
visible and wait. And wait. So far, I would call the results inconclusive.

It鈥檚 really not all that far-fetched an idea, though. Females of other
species copy the preferences of their peers all the time. Female quail, for
example, prefer a male they have just seen copulating. And female guppies go for
the more popular male, even if he is a bit of a wimp. Now researchers at the
University of Louisville, Kentucky, have compelling evidence that
people鈥攑articularly women鈥攅ngage in mate copying too. Just hearing
that other women want to date a man piques their interest.

The effects of peer attention could factor into a variety of social
phenomena: why a bushy beard and tangled locks were sexy in the seventies but
today鈥檚 hair can鈥檛 be short enough, or why teens pierce parts of their bodies
adults rarely even think about. They could help explain the unexpected sex
appeal of Mick Jagger or Jack Nicholson, and may be at work in celebrity of all
kinds. Everyone wants to be unique, but when it comes to mating, imitation
appears to have some powerful evolutionary advantages.

Until recently, all the evidence of mate copying has come from fish and
birds. That鈥檚 partly because it鈥檚 easier to spot in these animals than in
humans. Male grouse, for example, gather at special sites called leks where all
the action takes place. Leks are the grouse equivalent of a singles bar. Here
they strut around displaying their feathers in the hope of pulling a bird.
Females wander through the lek, choose a male, mate on the spot鈥攈ere the
singles bar analogy breaks down a bit鈥攁nd then head off into the
undergrowth to nest. Some males on the lek have all the luck. The most
successful may win up to 80 per cent of the passing females.

So what do the females see in these Casanovas? Some researchers suspected
that mate copying was initiating a snowball effect: once a few females chose the
same guy, the rest would come running. In 1994, behavioural biologists tested
this idea by placing several stuffed female dummies on a black grouse lek near
randomly chosen males. The eager cocks courted and mounted the dummies,
sometimes for up to half an hour, which gave passing females lots of time to
notice. Sure enough, the lucky males ended up mating with more real females on
that day than either the day before or the day after.

Other experiments in the lab showed a similar effect in fish known as river
bullheads. Unlike male grouse, who play no part in raising their offspring,
bullhead males are attentive fathers. They guard the eggs and stay with
hatchlings until they are old enough to survive on their own. And female
bullheads will always try to spawn with males that already have nests containing
eggs. It looked as though both grouse and fish females were copying others as a
shortcut to finding a good mate.

True, there are other explanations for these behaviours. In the case of the
grouse, the females might simply have been stimulated by the sight of the males鈥�
prolonged encounters with the dummies鈥攏ormal grouse copulations are almost
instantaneous. Similarly, bullhead females might have other reasons for their
preference. For example, by laying their eggs in nests that are already
occupied, they decrease the chances of them being eaten by predators.

But such objections to mate copying have been sidelined in recent years, in
part because of the work at Louisville by biologist Lee Dugatkin. In 1996,
Dugatkin got female guppies to change their mind about which male they liked
best solely on account of the preferences of other females. Normally, female
guppies like orange. Given a choice, a female will go with the brightest orange
male she can find. This may be because the most vividly coloured males tend to
be the boldest, and will confront approaching predators. (The researchers added
weight to this idea with an experiment in which they trapped a drab male in a
glass cylinder and held him right up close to a large fish. Females that saw
this happening subsequently preferred this drab male to a more orange one held
further away.)

Dugatkin and his colleagues wanted to see if they could override the fish鈥檚
genetically based preference for orange. They built a fish tank with two smaller
tanks attached, one containing an orange male and the other holding a drab one.
A female plopped in the middle tank would court the orange male through the
glass. The same female was liable to change her mind, however, if she was first
held in the middle by a clear cylinder while a second female was trapped by a
Plexiglas divider so that she could only swim close to the drab male. For want
of anything better, she courted the drab male. When she was removed, along with
the dividers, the original female would start courting the drab male rather than
the orange one.

Several other cases of mate copying have been reported since then. Last year
David White and Bennett Galef of McMaster University in Ontario reported
findings from a similar experiment with Japanese quail using cages instead of
tanks. In this case, the males were equally 鈥渁ttractive鈥� but one was allowed to
mate with a female for ten minutes, while the other was by himself. When the
cages were lifted, the female most often courted the male that had just mated.
Similar studies have also turned up mate copying in Japanese madaka fish,
sailfin mollies and swordtails.

The prevalence of copying suggests it must give the copier some edge in
evolution, though exactly what this is remains unclear. One good reason for
copying might be that it saves time choosing a mate鈥攖ime that could be
spent doing other things, such as eating or looking out for predators. Or it may
be simply that choosing a quality mate is tricky, and by watching what others
do, you get more information on which to base this tough choice. This strategy
fails, of course, if the individual you copy knows less than you do. But the
fact that young guppies tend to copy old ones rather than the other way around
suggests that here, at least, copying may be a way of passing down accumulated
wisdom.

Birds and fish aren鈥檛 renowned for their intelligence, though. So perhaps
they rely on imitation because they tend not to do much thinking on their own.
They follow the flock. They go with the flow. Would independent-minded human
beings, with the power of reason and free choice, care about the choices other
people make?

To find out, Dugatkin teamed up with psychologist Michael Cunningham, also at
Louisville. They presented 166 female undergraduates with a report ostensibly
written by five of their peers after a 20-minute interview with a man named
Chris. In fact, the five women and Chris were all fictitious. The reports ranked
Chris鈥檚 physical attractiveness on a scale of 1 to 10, and indicated how many of
the women were interested in dating him.

The reports rated Chris as either a 3 or a 10 in attractiveness. In addition,
four, one or none of the women said she was interested in dating him. Once they
had read the reports, the women undergraduates were asked how interested they
might be, on a scale of 0 to 6, in dating Chris. A high attractiveness rating
raised the women鈥檚 interest by just over a point on average compared with a low
rating. But peer attention had a stronger effect, raising the average dating
interest by one-and-a-half points. 鈥淭he underlying assumption is that he must
have something going for him,鈥� says Cunningham. 鈥淚f other people are attracted
to him, he must have something they want.鈥�

Men are influenced by their peers too, but not nearly as much as women.
Running the same experiment on a similar number of men with all the sexes
reversed鈥攂ut keeping the androgynous name, Chris鈥擠ugatkin and
Cunningham found that while men responded similarly to the attractiveness
ratings, they relied less on other men to decide whether they were interested in
Chris. High peer attention boosted their mean interest by less than a point in
most of the experiments.

The difference between men and women was even more pronounced when they were
asked to rank their interest in marrying Chris. In this case, high peer
attention raised the rating given by the men by barely half a point on average,
whereas the women鈥檚 interest jumped by two to three times as much.

This is exactly what evolutionary theory might predict about mate copying. In
most species females tend to be more picky than males. That鈥檚 because they
usually invest much more time and energy than males in raising their offspring,
so choosing the best mate pays big dividends. Males, on the other hand, can
afford to be a bit more cavalier. 鈥淪o males tend to use a smaller subset of
information to determine what they are interested in,鈥� says Dugatkin.

What exactly are women looking for in a mate? Dugatkin and Cunningham found
that women (and men) were strongly influenced by the peer attention rating when
forming opinions about Chris鈥檚 various attributes. Regardless of the beauty
rating, if four peers were attracted they said Chris must have a good sense of
humour and good social skills, and, they said, Chris must be wealthy. These
qualities are attractive because they suggest that Chris will be a good parent
and provider.

Studies suggest that wealth may be particularly important to women. Over a
decade ago, David Buss, an evolutionary psychologist from the University of
Texas at Austin, surveyed the mate preferences of some 10,000 people across 37
cultures. He found that women universally placed greater importance than men on
good financial prospects as well as related factors such as status and ambition.
More recent studies show that these factors weigh much less heavily with women
in highly paid, high-status jobs, suggesting that the importance women place on
wealth is linked to their own socioeconomic status.

To see just how powerful an influence wealth could have on Chris鈥檚
attractiveness, Cunningham and Dugatkin did another experiment in which they
added a description of Chris as a humanities major with the potential to earn
only about $20,000 a year. For half of the subjects, they added that
Chris鈥檚 parents had won $10 million in a sweepstake and set up a trust
fund for Chris that would pay him $500,000 a year.

Personal wealth

When all other variables were the same, wealthy Chris sparked slightly more
interest among both females and males than poor academic Chris. But the impact
was much smaller than Dugatkin had expected, possibly because the money said
nothing about Chris鈥檚 abilities. 鈥淥ne reason people would care about wealth is
as an indicator of ambitiousness and personality overall,鈥� says Dugatkin.

In some sense, then, being a rich person might be like being an orange guppy.
Peer attention overrides orange colour in guppies, unless, Dugatkin has found,
the guppy is very orange indeed. Then peer attention no longer gets the female
to switch. In humans, what counts may be the ability to generate money rather
than simply having lots of it. So the question is, if Chris had an earning
potential of $500,000 a year, would that override the peer attention
effect? It鈥檚 certainly possible, Dugatkin says, but the experiment has still to
be done.

What does any of this have to do with everyday life? 鈥淭he phenomenon of
groupies is relevant,鈥� says Buss. 鈥淵ou get fairly geeky-looking guys generating
a sort of mass hysteria which might be a mate copying phenomenon.鈥� Chances are
that few teenage girls swooned over John Lennon before the Beatles were
famous.

That sort of celebrity then leads directly to another kind of imitation. By
the mid-1960s most young men were trying to look like the Beatles, then later
Led Zeppelin and Depeche Mode. Today it鈥檚 Eminem or David Beckham. 鈥淢ate copying
does help us explain why there is a great deal of variation across societies and
across time in what we find attractive about the opposite sex,鈥� says Dugatkin.
Trends in clothing, hairstyle, even body piercing, are so volatile because of
peer attention鈥檚 snowball effect.

As for the wedding ring effect, the hunt goes on. A few years ago, Cunningham
and his colleagues tried an experiment in which women sat alone at a bar with a
wedding ring clearly visible. But the results were inconclusive. 鈥淐hoosing
females may have been a tactical error,鈥� Cunningham says. 鈥淚f she is an
attractive enough female, whether she has a wedding ring or not, there is a high
base rate of being approached.鈥�

He has not yet tried the reverse experiment, with men waiting at the bar, in
part because the base rate of women approaching men is quite low. Many more
hours of observation would be required to detect an effect鈥攁s I can
personally attest. 鈥淭he way the ballet usually works is that the female makes
eye contact and smiles,鈥� says Cunningham. 鈥淏ut it鈥檚 still the guy who has to get
up off his stool and move.鈥�

So I鈥檓 getting off the stool and heading home. I am, after all, happily
married.