Chapter One
Monkeyluv
Well, I have some terrible news for 99 percent of us never destined to
make People’s Most Beautiful issue and thus get to be featured in essay
one. This news is so terrible that it’s even been reified with a cover
story in Newsweek. But first, a Martian joke:
So the Martians finally come to Earth and they turn out to be great folks.
Earthlings and Martians hit it off, sit around for days talking about
politics, the weather on Mars and Earth, sports, what really happened with
Elvis…. Eventually, both the earthlings and Martians feel comfortable
enough to work up the nerve and ask the other folks what they’re really
curious about – “So how do you guys reproduce?”
It’s decided to have a demonstration. The Martians go first. Four of them
stand on top of each other, make whirring mechanical sounds, lights go off
on their foreheads, smoke and bells, and … suddenly, a new Martian pops
out.
“Fabulous, just fabulous, love the concept,” say the earthlings. Then it’s
our turn. A suitable volunteer couple has been found, a bed cleared, and
the couple goes at it while the Martians stand around taking souvenir
photos. The pair finishes in a sweaty heap.
“Great, that was terrific, very novel,” enthuse the Martians, “but one
thing … er … where’s the new earthling?”
“Oh, that,” they are answered. “That happens nine months from now.”
And the Martians ask, “So why were they in such a rush at the end?”
So why are we in such a rush at the end? We animals will swim upstream and
leap over dams, will spend hours butting heads with other antlered beasts,
will laugh at someone’s stupid jokes, all for the chance to mate, to get
into that special circumstance where we are in such a rush at the end.
What is it that drives us to do so? Is it for the good of the species?
Nah – that style of thinking went out with Marlin Perkins. How about its
being for the good of the individual? “By mating as frequently as
possible, you maximize the number of copies of your genes in the next
generation and thereby enhance your reproductive success in the general
population pool.” Yeah, right – how many animals bring
evolutionary-biology textbooks to bed with them? Option three: Because it
feels good. Of course.
What we have here is a dichotomy between the distal and proximal
explanations for the same behavior. Distal: the long-term, underlying
explanation for why something happened. Proximal: the short-term,
nuts-and-bolts explanation. For example, a female primate gives birth to
an infant and, against any sort of logic, exhausts herself caring for it,
hauling it around, giving up calories and foraging time, making herself
more vulnerable to predators with this cumbersome burden. Why toil away
with this maternal behavior? Distal explanation: because among primates,
high degrees of maternal investment increase the likelihood of survival of
the offspring and thus maximization of passing on copies of genes.
Proximal explanation: because something about those big eyes and ears with
that wrinkly little face and, I can’t stand it, that adorable round
forehead, and you just have to take care of that kid.
Much of behavior is driven by proximal cues, and never is this more the
case than when thinking about the motivation for sexual behavior. For
behaviors that are that evolutionarily vital, that so often involve risk
to life and limb, the motivation can’t be abstract and delayed, like the
consequences for genetic competition, or for the promise of offspring
after a long gestation period (just imagine how few elephants there would
be on earth if elephant sex were motivated purely by the cognitive
recognition that, do this and, shazzam, two years later some kid pops
out). Sexual behavior has to be driven, overwhelmingly, by proximal cues.
Animals, including human beings, are interested in sex because it feels
good.
Now that the Gentle Reader is clear about this fact, the question gets
more interesting: What proximal cues are the most reinforcing for sex?
Basically, what makes one organism sexy to another?
Remarkably enough, scientists have a pretty good sense by now of what
qualities give us vertebrates the hots, and there are some consistencies
across the animal kingdom. For starters, species from birds to humans seem
to like the looks of someone who is average, symmetric in their face and
build – the archetype of conventional beauty. People, for instance, can
pick up incredibly subtle asymmetries in eyes, ears, wrists, or ankles,
and those definitely count against a potential mate.
Why prefer symmetry? The generally accepted explanation is that this
signals conventional health (although, as was the point of “Antlers of
Clay,” you should be cautious about automatically assuming that a case of
healthy symmetry is due to genes). This attraction toward averageness
accounts for a truly disturbing finding discovered soon after the
invention of photography: if you superimpose the pictures of a whole bunch
of human faces (or, nowadays, if you generate a computerized average of
them), you get this really good-looking imaginary composite android face.
But certain outliers exert an even more magnetic attraction than the
averagely healthy. In species after species, the proximal signals
generated by females with higher than average appeal are ones indicating
atypically high degrees of reproductive potential. Most males in most
species respond to whatever their species’ equivalent is of a woman with
big-time child-bearing hips. And in the numerous species in which males
are selected for traits that differentiate them from females, the
exaggerated male traits that make hearts throb are those implying
successful male-male competition – their equivalent of being buffed up,
or possessing a territory or a high rank in a hierarchy. When taken to an
extreme, the sexy male in many species is the metabolic equivalent of
being economically well-endowed. As reviewed in “Antlers of Clay,” this is
the strange arena of secondary sexual characteristics among males, the
enormous plumage, the wild coloration, the strange appendages. It is a
sign of peacock strutting, of conspicuous consumption – “I am so healthy,
so parasite-free, so well-off, that I can afford to waste all these
calories on something as ridiculous as these huge neon antlers.”
So throughout the animal kingdom, individuals of both sexes respond to the
conventionally attractive all-American kid next door, but especially
respond to the drop-dead gorgeous individual with the amazing
________________ (fill in according to your species and gender). Those are
the sorts of traits that provide particularly strong proximal cues toward
mating. Now, the demoralizing fact confirmed by Newsweek, the one that all
of us run-of-the-mill-looking folks knew all along, is that animals who
generate those strong proximal cues get treated better. I don’t just mean
that good-looking vertebrates get to be more sexually active. They get
treated better in all sorts of walks of life.
That’s not news, of course, when it comes to humans. Study after study
shows that we will listen with rapt attention to someone’s raving
gibberish, will preferentially give them a job or even vote for them, just
because they have gorgeously symmetric wrists. The ones I’m really
disappointed by are the nonhuman primates, who are usually more sensible
than that.
A study by the ethologists Bernard Wallner and John Dittami of the
University of Vienna shows a pretty egregious example of such preferential
behavior among Barbary macaque monkeys. When a female comes into heat, she
develops a conspicuous anogenital swelling that tells the world of her
special ovarian status. Although the size of the swelling increases as a
female approaches her ovulation day, some females have bigger swellings
than others. And those females get treated better. When compared with
females at the same point in their reproductive cycles who have smaller
swellings, the well-endowed females are less likely to have males in bad
moods displace aggression onto them. Moreover, males are more likely to
groom them. Okay, so male macaques get gaga over pneumatic anogenital
swellings. The ones who should really know better than that are the
females. But they do it too – big-swelling individuals are preferentially
groomed by females as well.
This is depressing as hell. Is there a phylogenetically widespread bias to
treat individuals by how they look? Is all of evolution from slime molds
on up one dazzling trajectory leading to the unlikelihood that Dan Quayle
was once vice president? But it turns out that things may not be that bad
after all.
A first example of some redeeming sensibility comes from an unlikely
source, namely us humans. As discussed in “Antlers of Clay,” the
psychologist David Buss carried out a celebrated study concerning how
people choose their mates, surveying more than ten thousand people from
thirty-seven different cultures around the planet. As was noted, in every
society studied, women placed a disproportionate emphasis in their mate
preference for someone with good economic prospects. In contrast, in
society after society, men disproportionately valued youth, someone who
possesses the physical features that signal health and fertility.
Fair enough. But what was less reported was a commonality among the women
and men of all these different cultures – highest on everyone’s list was
finding a mate who was kind and who loved them.
Isn’t that sweet? Okay, let’s be sour cynics for a moment. Buss was
surveying what people look for in a mate, not whom they’d like to jump
into the sack with right now. Ultimate issues, not proximal ones. Maybe
when people are contemplating whom they want to grow old with, a sensible
distalness predominates: it makes sense to go for someone who is kind,
loving, capable of being a good parent, someone who will remember to put
the cap back on the toothpaste. But when we put ourselves back into the
realm of proximal cues, it might be that the person who makes your blood
run scalding has none of those traits, has bad news written all over them.
It seems unlikely that kindness is ever sexy.
Yet the evidence can be surprising.
In recent decades, a revolution has taken place in primatology. It had
been thought that sexual behavior among Old World primates (the kinds that
live in big social groups, like baboons or macaques) followed a “linear
access” model: if a single female was in heat, the highest-ranking male
would claim her. And if two females were in heat, males number one and two
would mate with them, and so on. The mating patterns were assumed to arise
exclusively from the outcome of male-male competition; the females
passively wound up with whomever the competition allotted them.
The revolution was the discovery of “female choice,” the wildly radical
notion that females had some say in the matter. Maybe this had something
to do with there having been a transition, such that the best
primatologists around were female, and with their looking at the behavior
of their animals without that linear-access bias. What was obvious was
that some females didn’t just passively wind up mating with whichever hunk
strutted forward. Being half the size of males in many of these species,
females couldn’t convince a male they didn’t favor to get lost by beating
on him.
But they sure could fail to cooperate. Maybe a female wouldn’t stand still
when the male tried to mate. Maybe, when pursued by a male, she would
repeatedly walk right past the male’s worst rival, forcing the two into
tense interactions. And with any luck, those two male rivals would get so
haired out with each other that they would collapse into fighting, giving
the female the opportunity to sneak off to the bushes and mate with the
guy she is really interested in (a phenomenon called stolen copulations,
as well as other, unprintable terms, by primatologists).
But if the female has a choice, who does she choose? Who does attract her
to the bushes? The answer, at least among baboons, is stunning: the nice
guy. Maybe it is a male with whom she has a “friendship,” or a mutual
grooming relationship. Maybe he carries her kid to safety when predators
are around. Maybe he is the father of that kid. But basically, he is a
male who is now favored because of the quality of the relationship he has
worked out with her over time – not because he has won some fight with
another male.
Let’s be clear about what’s happening. This is not the case of a female
thinking, in effect, Okay, that big hunk over there in the biker jacket is
really hot, but be sensible, kiddo, the guy’s trouble, better stick with
kindly Alan Alda. Just the opposite. These females are manipulating these
big, dangerous studs into fighting with each other, are risking life and
limb (as they are occasionally subject to fatal displacement aggression at
the teeth of those frustrated males), all to sneak off to the bushes to
have sex with the Alan Aldas of their society. Think about it: nice can be
proximally sexy.
This is extraordinary. And even more extraordinary, genetic studies of
paternity have shown that in some species, male primates who bypass overt
male-male competition and instead covertly copulate in the bushes do
pretty well for themselves in the task of passing on copies of their
genes. By the coldly calculating bottom line of evolution, this niceness
business is not just some foolish sentimentality; it’s a successful
strategy.
So let your average, callow primate get all crazed and libidinous over how
someone looks or smells. For the monkey who actually cares about how he
treats someone, the evolutionary payoff is at least as great. This is
pleasing news on a proximal level: even for a nonhuman primate, the most
erogenous organ can be the mind. Or the heart. And this is pleasing news
on an ultimate level as well, for all of us who have been tempted to
jettison our kindergarten lessons about being nice and sharing in favor of
sad adult jadedness about looking out for number one. Maybe that
notoriously asymmetric sage Leo Durocher was wrong with that business
about nice guys finishing last.
(Continues…)
Scribner
Copyright © 2005
Robert M. Sapolsky
All right reserved.
ISBN: 0-7432-6015-5
Excerpted from Monkeyluv
by Robert M. Sapolsky
Copyright © 2005 by Robert M. Sapolsky.
Excerpted by permission.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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