The Male Brain (9 page)

Once Ryan had a taste of Nicole, he was hungry for more. Although he was desperately craving her, he knew he had to wait a few days before calling her, or he'd look too eager. Showing his burning desire wouldn't do him any favors right now, particularly because
Nicole was being so cautious
. Researchers found that when a man is sexually attracted to a woman, he wants to have sex with her as soon as possible. For the men in the study, waiting a week or more seemed like a very long time. The women, on the other hand, wanted to wait
up to three times longer
. As much as Ryan was secretly hoping for sooner rather than later, he could tell that Nicole wasn't the type to rush into
anything, least of all sex
. While that was frustrating on one hand, it was also reassuring and made him think she might be in the long-term mating category.

In the basest way, to a man, winning the mating game means getting his DNA and genes into the next generation. Even though he isn't consciously thinking this, the instinctual part of his brain knows that the more women he has sex with, the more
offspring he's likely to have
. Meanwhile, the female brain is trying to discern whether a man has what it takes to be a good protector and provider. Researchers find that this holds true regardless of a woman's level
of education or financial independence
. When Ryan called and invited Nicole out to dinner and a movie, she suggested that they go Dutch--just to eliminate the pressure for sex she sometimes felt when she let men spend money on her. But Ryan wanted to pony up resources to demonstrate how much he valued her
and was willing to invest
. In studies of mating behavior in primates, biologists have discovered that females have more sex with
males who bring them meat
. Primatologists have dubbed this the meat-for-sex principle. The males who showed they were willing to provide food got more sexual access to the females, increasing their chances of paternity. Ryan was on the right track.

He liked treating Nicole like a queen, and he had no qualms about spending money on her. But by their fourth date he was burning with sexual desire. He thought he'd better come up with something persuasive fast, or he'd die of sexual frustration. Gifts, flowers, or the promise of a romantic getaway weekend--he was thinking of them all. As men well know, they have to develop and refine an array of smooth tactical maneuvers, because women have different mating goals than men have. The female brain wants the hope of love and commitment before having sex, but for
men, sex often comes first
. Not surprisingly, it was Ryan's philandering teammate Frank who came up with the winning idea. "Take her to our rugby game this weekend, dude. Let her see you in action." Researchers have shown that nothing serves as a better aphrodisiac for women than a show of dominance and strength.
Nicole had never been to a rugby game and was surprised by how rough it was. She loved seeing Ryan steal the ball and take it downfield for the winning point, and Ryan loved knowing she was in the stands watching. She couldn't believe how turned on she was by his sweaty body. After the game, he glowed under the approving looks she was sending him and basked in the envy he saw on his teammates' faces. Ryan was pleased that this strategy seemed to be working.

While humans and animals have differences in their mating strategies, scientists have observed some curious similarities. One of the most colorful examples of animal tactics is provided by the
side-blotched lizard
(Uta stansburiana)
. Conveniently, the males come with three different colored throats that match their mating styles. Males with orange throats use the alpha-male harem strategy. They guard a group of females and mate with all of them. The males with yellow throats are called sneakers because they slip into the harem of the orange throat and mate with his females whenever they can get away with it. The males with brilliant blue throats--my personal favorites--use the one-and-only strategy. They mate with one female and guard her 24/7. From a biological perspective, the approaches of the orange-throated harem leader, the yellow-throated sneaker, and the blue-throated one-female type are all successful mating strategies for lizards and for human males, too. I affectionately call my husband a blue-throat.

So, women may be anxiously asking, "
How can I pick a blue-throat
?" We have no surefire answer yet on what makes for a monogamous human male mate, but research on furry little mammals called voles might provide some clues. Scientists have found that male prairie voles are monogamous and share equally offspring. But their cousins--the strictly promiscuous, seek sexual variety, and specialize in one-night stands that last less than a minute. The difference between the mating strategies of these vole cousins originates in the brain. When the prairie vole finds his partner, he mates with her over and over in a twenty-four-hour sexual marathon. This sexual activity changes his brain forever. An area of his brain called the AH--the anterior hypothalamus--memorizes his partner's smell and touch, leading him to
aggressively reject all other females
. This blissful day in the new vole couple's relationship is not only unforgettable, but biologically necessary. Memorizing her and thus merging the so-called love and lust circuits in his brain will initiate a lifelong
preference for this one female
.
in parenting their

During sex, both prairie and montane voles release vasopressin and dopamine, but only the prairie vole has the type of vasopressin receptors in his brain needed to make him monogamous. And when scientists experimentally blocked these monogamy-inducing vasopressin receptors in the prairie voles' brains, they didn't
bond with their sexual partners
. The love and lust circuits
in their brains couldn't merge
. What makes the difference between the vasopressin receptors in the prairie vole brain and the montane vole brain is their differing genes. The monogamous vole's vasopressin receptor gene is a longer version, and the promiscuous vole's is a shorter version. When scientists inserted the long version of the gene into the promiscuous montane
vole, he, too, became monogamous
.

Although the brain biology in men may turn out to be more complicated than it is in voles, humans have
this vasopressin receptor gene too
. Some men have the long version, while others have the short one. A study in Sweden found that men with the long version of the vasopressin receptor gene were twice as likely to leave bachelorhood behind and commit
to one woman for life
. So when it comes to fidelity, the joke among female scientists is that "longer
is
better," at least when it comes to the length of the vasopressin receptor gene.

Ryan's friend Frank was a confirmed bachelor and a master of seduction. He had well-rehearsed lines and knew exactly what to say and do to score sexual points. Phrases like "You're so beautiful you should be a model" and "I've never met a woman like you before" may be cliches, but Frank was so gorgeous and charming that women were ready to believe his little deceits. And according to studies, Frank has plenty of company in this "no strings, no commitment" mating strategy. They showed that deception serves as an important part of men's
mating strategy for short-term partners
. And researchers found that three out of four men said they were willing to lie or "modify the truth" to persuade women
to have sex with them
. They found that the things dating men lie about are similar around the world. Men exaggerate their wealth, status,
and business and social connections
. Frank frequently exaggerated his income and financial prospects and rarely missed a chance at name-dropping.

Now that Nicole and Ryan were seeing each other a few times a week, she sometimes heard Frank bragging about his latest conquests. She was so put off by his maneuvering that she tried to warn his newest girlfriend, Stacey. But it was no use. Stacey's brain and body had already fallen under Frank's seductive spell. What she didn't know was that each time she and Frank had sex, she was falling a little more in love--the oxytocin released during her orgasms was binding her body
and brain closer to Frank
. But it was working the other way around for him. He was starting to get bored. The more Stacey tried to pin him down to future plans,
the more he squirmed
. He felt it was time to move on. No cage of domesticity for him.

To be sure, both men and women try to manipulate the mating game. But when it comes to using verbal deception, researchers have found that men are biologically more comfortable with it than women. They measured the vocal strain of men and women telling lies to the opposite sex and found that the men showed much less
electrical strain while they lied
. This allowed the men like Frank to deceive in a more convincing manner. Ryan was glad Nicole didn't meet Frank first, because he knew Frank would have made a play for her immediately. She didn't seem like the type to fall for Frank's short-term mating style, but he'd been wrong about women before.

When Nicole finally invited Ryan to spend the night, he felt like he'd died and gone to heaven. After that, they made love every day, sometimes more than once, and he still
couldn't get enough of her
. Sex doesn't always lead to love, but for the male brain, it is a
necessary part of getting there
.

Ryan's brain on sex was producing chemicals that create a blissful euphoria, similar to being high on cocaine. He couldn't figure out why, when he was away from Nicole for more than four or five hours, he started
getting a primitive biological craving
. If we could travel along Ryan's brain circuits on a miniature train as he was falling in love, we'd begin in an area deep at the center of his brain called the VTA, the ventral tegmental area. We'd see the cells in this area rapidly manufacturing dopamine--the brain's feel-good
neurotransmitter for motivation and reward
. As the train was being filled with dopamine at this VTA station, Ryan was starting to feel a pleasant buzz.

Filled with dopamine, the train would speed along his brain circuits to the next station, the NAc, or nucleus accumbens, the area for
anticipation of pleasure and reward
. Because Ryan is male, we'd see the dopamine from the train being mixed with testosterone and vasopressin. If you're female, it gets
mixed with estrogen and oxytocin
. Mixing dopamine with these other hormones was now making an addictive, high-octane fuel, leaving Ryan exhilarated and
head over heels in love
. The more Ryan and Nicole made love, the more addicted
their bodies and brains became
.

When the lovebirds were apart, they were constantly thinking about and texting each other. The love train with its addicting fuel makes it so we can't stop thinking, fantasizing, and talking about the person we're in love with. In one study, men and women said they spent up to 85 percent of their waking
moments daydreaming about their lover
. Ryan felt as if he were literally incorporating Nicole's essence into the fabric of his brain circuits. And he was. As the train sped into the final station, the caudate nucleus, or CN, the area for memorizing the look and identity of whoever is giving you pleasure, we'd see all the tiniest details about Nicole being indelibly chiseled into his permanent memory. She was now literally unforgettable. Once the love train had made these three stops at the VTA, the NAc and the CN, we'd see Ryan's lust and love circuits merge as
they focused only on Nicole
.

Ryan was starting to think of Nicole as "the one," and he was determined
to hold on to her
--so much so, Nicole told me, that when other guys were around, Ryan was sure to take her hand or possessively put his arm tightly around her.

When she came in for her appointment, she said, "I like it that he's so protective, but it seems a little hypocritical. I mean, just a couple weeks ago I caught him checking out a girl with big boobs at the car wash."

She told me that Ryan had been putting the quarters in the coin slot when a minimally dressed twenty-something walked by. "You should have seen the look he gave her. I know guys look at other women, but I can't believe he did it right in front of me. Maybe he's more like Frank than I thought."

I told Nicole that the lust center in the male brain automatically directs men to notice and visually take in the details of attractive females. When they see one that lights up their sexual circuit board, their brain instantly produces a quick sexual thought, but then it's usually over. To Ryan's mating brain, the buxom woman was like a bright, colorful hummingbird. She flew into his line of vision, caught his attention for a few seconds, and then flew off and out of his mind. For many men, this can
happen several times a day
. Ryan couldn't have stopped his eyes from looking at her breasts even if he'd tried. But he could learn to be more discreet. Because this is an autopilot behavior for the male brain, men don't think it's a big deal, and they can't understand why women find it so threatening. Until the tables are turned.

Unbeknownst to Ryan, Frank was looking forward to an upcoming rugby game for reasons that went beyond his need to beat their biggest rival. He was secretly excited about Ryan being out of town that weekend, leaving Nicole alone and "unguarded."

Not wanting to raise Ryan's suspicions, Frank waited until just an hour before the rugby game to casually text Nicole and ask, "Want a ride to the game?"

She was on her way home from work, and going to the game sounded like more fun than going home alone. "Sure," she texted back.