Analog SFF, April 2010 (11 page)

This neurotransmitter cocktail, Fisher says, is an even stronger drive than sex itself. “People in stories kill for love, live for love, and die for love,” she says. Cupid's arrow is tipped with dopamine.

Rejected lovers had similar brain activity, plus some in regions of the brain active in cocaine addicts. No surprise, Fisher suggests. “Romantic love is an addiction when it's going well and horrible when not."

The long-term lovers were a bit different. They still showed activity in some of the flashy dopamine centers, but also had activity in parts of the brain associated with producing our friend oxytocin. “They're feeling not only romantic love, but also deep attachment,” Fisher says. They also exhibited a lot of activity in a serotonin-producing region associated with calmness. “These people are in love, but that early intenseness and anxiety is now replaced,” Fisher says.

How does kissing affect this? Well, new experiences stimulate dopamine and norepinephrine. “And certainly the first kiss is wildly novel,” Fisher says. “So it's entirely possible the novelty, [by] driving up dopamine and norepinephrine, could also trigger the brain system for romantic love."

Combine this with Hill's oxytocin/cortisol research, and other groups’ findings regarding sex hormones in saliva, and it appears there's a lot going on in a “simple” kiss. In fact, Fisher suggests, it may have evolved to stimulate all three of the brain's relevant hormone/neurotransmitter systems. “[The] sex drive got you out there looking for a range of partners,” Fisher says. “Romantic love got you to focus on one at a time. Attachment evolved to at least allow you to tolerate this human being long enough to raise a child together."

But Cupid doesn't hit everyone equally. Some people are strong in one neurotransmitter, some in another. Some appear to produce large amounts of one hormone, some another.

To learn more, Fisher teamed up with online dating giant match.com to determine what type of biochemistry produces the type of relationship chemistry we all crave.

Going into the partnership, she had determined that there were four basic hormonal/neurotransmitter types, or patterns: dopamine/norepinephrine, serotonin, testosterone, and estrogen/oxytocin. So she developed a survey to distinguish them—a sort of biochemical Myers-Briggs personality inventory. “We got seven million responses,” she says.

The four groups were quite distinctive. “Dopamine is more risk-taking, novelty-seeking, [and] creativity,” she says. “Serotonin is calm, social, cautious but not fearful."

High-dopamine people have energy and optimism and are good idea generators with many interests. They're also curious and verbal. Think “Obama,” she says. But they can be easily bored, impulsive, reckless. Addiction is a possibility. The word they're most likely to use in their online ads is “adventure."

High-serotonin people are more conventional. They have more close friends, are good at cooperation, and are persistent, stoical, conscientious, and tend to be more religious. But they can also be stubborn, closed-minded, rigidly moralistic, and controlling. In their ads, the most important words were “family,” “loyal,” “respect morals,” “trustworthy,” “caring.” They also tend to be rural. “I could point out the red states and blue states and see where the serotonin and dopamine was, and why these people don't understand each other,” Fisher said. “The whole language is different."

As an example of a high-serotonin person, Fisher suggests George Washington.

High-testosterone people are analytical, direct, decisive, tough-minded, work well in “rules-based” systems, and are good at math, computers, chess, and music. They're also emotionally contained. “If you watch a high-testosterone person on television, they're really only moving their lips,” Fisher says. “They're not moving much of the rest of their face at all.” The downside is that they can have poor verbal skills and be aggressive and uncompromising.

"I think John McCain is a perfect example,” Fisher says. “He was proud of being a maverick.” Not that this category is exclusively male. Fisher puts Hillary Clinton in the same group.[8]

Estrogen is usually viewed as a female hormone, but men can express it as well. “Football players have been found to be high estrogen as well as testosterone,” she says.

If you're looking for a good example, she says, think the other Clinton: Bill. Such people are consensual, holistic, able to see the big picture. They're imaginative, linguistic, intuitive and emotionally expressive, and have strong verbal and social skills. But they can also be indecisive, unfocused, gullible, effusive, ruminating, and unforgiving.

In dating ads, their favorite words are “passion,” “real,” “heart,” “kind,” “reader,” “sensitive,” “sweet,” “empathic."

Again, she points to the former President Clinton. “
I feel your pain
,” she says. “Only this type would say that.” And she notes, “His book was 963 pages. We all know he can't stop talking."

So who do these people pair up with?

In most cases, Fisher says, similar brain chemistries attract. High-dopamine/norepinephrine people go with high-dopamine/norepinephrine people; high-serotonin people go with high-serotonin people. In other words, “adventurous” people go with other “adventurous” people and traditionalists want traditionalists—with the obvious caveat that other factors play big roles, ranging from intelligence and socioeconomic background to childhood experiences and religious preferences.

A lot of this makes biological sense. Emotionally, people who mate with similar neurotransmitter types are going to agree. High-serotonin types may both want to build a family, go to church, have a traditional Thanksgiving, etc. One question Fisher asked was whether people would rather have loyal friends or interesting ones. Only the serotonins preferred loyalty. “We all want loyal friends,” Fisher said, “[but] the other three can't tolerate uninteresting friends."

The exception to likes attracting are the testosterone people. “Testosterone goes for estrogen and oxytocin,” she says, again pointing to the Clintons. “In this case, opposites attract."

From an evolutionary perspective, she adds, high-dopamine people might be programmed to seek out mates with wide-ranging interests that expand their own. High-serotonin people might be seeking to reinforce their own strengths. And testosterone-estrogen pairs may seek each other out in order to combine divergent resources.

Not that all of this is written in concrete. It's possible, her survey found, to rank high on more than one of the four scales. “I've found people who are high on three of the four,” she says. “The outlier is serotonin. If you're expressive of it, you're low on the others, mostly."

All of this obviously has a lot to do with Valentine's Day, but what does it have to do with kissing? Possibly a lot. There's got to be a reason why so many cultures use kissing as a preliminary step in mate assessment. “I think we'll find that kissing is a real adaptive mechanism,” Fisher says. “The brain becomes very activated."

Her main point, though, is much simpler. “Who you choose to mate with is one of the most important things you do,” she says.

Thus, it makes sense that we have a lot of biological processes designed to help us do it right. On top of that is the fact that we have “these four very broad constellations” of personality types. “These play a role in attraction when you kiss."

So, when you kiss your sweetheart this Valentine's Day, remember that you might be exchanging a lot more information than you think. But remember also that humans are creatures of will and spirit as well as biochemistry. I know one couple (both high-serotonin types) who chose not to kiss until their wedding. A silver anniversary later, they're tightly enough pair-bonded you'd think they'd been mainlining oxytocin. Others worship from afar for months, or even years, before they finally acknowledge it. And then—well, it's
Princess Bride
time. Maybe the normal “kiss” signaling has been done by other means. Humans are, after all, complex creatures.

If we weren't, what fun would science fiction be?

Copyright © 2010 Richard A. Lovett

[FOOTNOTE 1: Not that this is required. “The default assumption is that people kiss in an erotic or romantic situation,” says Donald Lateiner, a professor of classical studies at Ohio Wesleyan University. “But there are other occasions.” In some cultures, for example, social kissing is common among people of equal status. In others, kissing can be a sign of deference or superiority. “[That's] sometimes called kissing up, or down,” Lateiner said. (An example would be kissing a bishop's ring.) But this article is timed to come out near Valentine's Day, so let's go with the cultural flow and focus on romance.]

[FOOTNOTE 2: Sometimes called philematologists (but don't try to find either word in the dictionary).]

[FOOTNOTE 3: Although, she notes, these were college students, so any efforts to generalize must take that into account.]

[FOOTNOTE 4: Being trapped for a quarter-hour with a bad kisser or someone with extreme halitosis might have that effect, but these were couples, not people who'd never kissed before.]

[FOOTNOTE 5: The citation is hard to find.]

[FOOTNOTE 6: M.D. Kirk-Smith and D.A. Booth (1980), “Effects of Androstenone on Choice of Location in Others’ Presence,” in H. van der Starre (Ed.),
Olfaction and Taste
(Vol 7., pp. 397-400).]

[FOOTNOTE 7: Ideally, such studies would involve kissing in a brain scanner. But, as one commenter at the AAAS symposium pointed out, it's hard to kiss in a brain scanner. “There's not much room."]

[FOOTNOTE 8: Nor are there any differences among gays and straights. Five hundred thousand gays have taken the survey in the U.S. alone, Fisher says, and the same four personality types emerge. “If you're a curious person, you're going to be curious, whether you're gay or straight. If you're stubborn, you're going to be stubborn, whether you're gay or straight. We're measuring temperament scales rather than sexual orientation."]

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It's not uncommon to hear a gripping story described as a “page turner,” but next month (May) we have a real one for you: “Page Turner” is its name. It's by Rajnar Vajra, so it won't surprise you to hear that it's not quite like anything you've ever read. But neither will it surprise you to find that, despite its close-to-home setting, it weaves a fascinating array of ideas, offbeat characters, and distinctly unordinary happenings into something uniquely exotic, highly entertaining, and memorable.

H. G. Stratmann is back with a story completely different from his recent series, while David W. Goldman, a newcomer who made a considerable splash with his first couple of stories here, returns with his first new one in much too long. The rest of the fiction line-up covers a wide spectrum with entries from Lee Goodloe, Walter L. Kleine, David D. Levine, and Rick Cook.

The fact article, by Stella Fitzgibbons, MD, sounds as science-fictional as anything else in the issue, but it's actually about things with which you may come (at least figuratively) face-to-face on your next hospital visit. It's called “Robots Don't Leave Scars: What's New in Medical Robotics?"

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There are things so pervasively important to people that it's hard to define their essence....

Seattle, 2010

I sit in the park, watching children play. I imagine their packs swinging as, earlier, they'd sprinted home from school, glad to be released into a spring afternoon. Later, dinner will be clanking silverware and gulps of milk. Then it'll be study time and bath time, with bedtime stories and goodnight kisses, reassurances in the hall as the light's left on. But for now, it's slides and jungle gyms, softball and tag.

It wasn't like I didn't know what I was doing when I chose the tenure track over the baby track. In the sciences, twice as many women as men are divorced or permanently single. But I'd always figured I'd be one who beat the odds. After all, I was dedicating my career to studying love, or at least the neurochemistry behind it. Think serotonin, norepinephrine, estrogen, testosterone—hormones with forms like snowflakes looking for matching snowflake-receptors in the brain. But I lost most of my grant funds today: the dream I'd nurtured just as surely as these parents nurtured theirs.

I see a small boy, two or so, with hair the color of straw and eyes like the sky. He wants to swing, like the older kids as they kick their feet up, daring each other to go higher. His mother helps him onto the seat, holding the chains as she gently pushes. Soon, he's far enough up for it to be scary, but she isn't going to let him fall, and he knows it. He's flying, pretending he's a big kid.

My research involves putting couples in brain scanners and watching the parts of their brains that light up as I try to puzzle out what it is that wires some for love, while others spend their lives searching. Sometimes, I give them printouts of their scans, small supernovas of brilliant hues set against black, the hieroglyphics of experience. When I see a good one, full of serotonin and dopamine and norepinephrine in just the right places—something my software renders in red and yellow the shade of a summer's-eve sun—I count it as true love.

The one I keep tacked above my desk is from an older couple, in their seventies. They eat lunches in the local buffet, play Boggle in the afternoon, spend summer evenings gardening. She likes petunias and he likes squash. “She makes the best fried squash around,” he'd said, squeezing her hand. Their scan reminds me that true love really exists. It thrives in Alice and Victor Burgess.

The two-year-old has had enough. Before he can start to fuss, his mother plucks him from the swing and bounces him on her hip. Toddlers have short attention spans.

My grant covered two grad students and a postdoc. Not much in the big scheme of things but in the calculus of grant committees, too much for too few papers. But doing science isn't like being a toddler on a swing. You can't just shut it off when someone decides you've had enough. As I walk from the playground, I make a decision. I've got six months left on an older grant. Not a lot of money, but enough, if I'm frugal. This project means too much to me. I'll continue as best I can.