The Science of Love: Biological Factors and Mating Rituals - Prof. Susan L. Handy, Exams of Environmental Science

Download The Science of Love: Biological Factors and Mating Rituals - Prof. Susan L. Handy and more Exams Environmental Science in PDF only on Docsity! Breeding is easy, but survival requires romance too. How our brains, bodies and senses help us find it Why We Love Time - January 28, 2008 Author: Jeffrey Kluger Reported by Eben Harrell / London Kristin Kloberd / Modesto, Calif. Kate Stinchfield / New York The last time you had sex, there was arguably not a thought in your head. O.K., if it was very familiar sex with a very familiar partner, the kind that — truth be told — you probably have most of the time, your mind may have wandered off to such decidedly nonerotic matters as balancing your checkbook or planning your week. If it was the kind of sex you shouldn't have been having in the first place — the kind you were regretting even as it was taking place — you might have already been flashing ahead to the likely consequences. But if it was that kind of sex that's the whole reason you took up having sex in the first place — the out-of-breath, out-of-body, can-you- believe-this-is-actually-happening kind of sex — the rational you had probably taken a powder. Losing our faculties over a matter like sex ought not to make much sense for a species like ours that relies on its wits. A savanna full of predators, after all, was not a place to get distracted. But the lure of losing our faculties is one of the things that makes sex thrilling — and one of the very things that keeps the species going. As far as your genes are concerned, your principal job while you're alive is to conceive offspring, bring them to adulthood and then obligingly die so you don't consume resources better spent on the young. Anything that encourages you to breed now and breed plenty gets that job done. But mating and the rituals surrounding it make us come unhinged in other ways too, ones that are harder to explain by the mere babymaking imperative. There's the transcendent sense of tenderness you feel toward a person who sparks your interest. There's the sublime feeling of relief and reward when that interest is returned. There are the flowers you buy and the poetry you write and the impulsive trip you make to the other side of the world just so you can spend 48 hours in the presence of a lover who's far away. That's an awful lot of busywork just to get a sperm to meet an egg — if merely getting a sperm to meet an egg is really all that it's about. Human beings make a terrible fuss about a lot of things but none more than romance. Eating and drinking are just as important for keeping the species going — more so actually, since a celibate person can at least continue living but a starving person can't. Yet while we may build whole institutions around the simple ritual of eating, it never turns us flat-out nuts. Romance does. "People compose poetry, novels, sitcoms for love," says Helen Fisher, an anthropologist at Rutgers University and something of the Queen Mum of romance research. "They live for love, die for love, kill for love. It can be stronger than the drive to stay alive." On its good days (and love has a lot of them), all this seems to make perfect sense. Nearly 30 years ago, psychologist Elaine Hatfield of the University of Hawaii and sociologist Susan Sprecher now of Illinois State University developed a 15-item questionnaire that ranks people along what the researchers call the passionate- love scale (see box, page 60). Hatfield has administered the test in places as varied as the U.S., Pacific islands, Russia, Mexico, Pakistan and, most recently, India and has found that no matter where she looks, it's impossible to squash love. "It seemed only people in the West were goofy enough to marry for passionate love," she says. "But in all of the cultures I've studied, people love wildly." What scientists, not to mention the rest of us, want to know is, Why? What makes us go so loony over love? Why would we bother with this elaborate exercise in fan dances and flirtations, winking and signaling, joy and sorrow? "We have only a very limited understanding of what romance is in a scientific sense," admits John Bancroft, emeritus director of the Kinsey Institute in Bloomington, Ind., a place where they know a thing or two about the way human beings pair up. But that limited understanding is expanding. The more scientists look, the more they're able to tease romance apart into its individual strands — the visual, auditory, olfactory, tactile, neurochemical processes that make it possible. None of those things may be necessary for simple procreation, but all of them appear essential for something larger. What that something is — and how we achieve it-- is only now coming clear. Page 1 of 7Multi-Print Viewer 2/13/2008http://infoweb.newsbank.com/iw-search/we/InfoWeb The Love Hunt If human reproductive behavior is a complicated thing, part of the reason is that it's designed to serve two clashing purposes. On the one hand, we're driven to mate a lot. On the other hand, we want to mate well so that our offspring survive. If you're a female, you get only a few rolls of the reproductive dice in a lifetime. If you're a male, your freedom to conceive is limited only by the availability of willing partners, but the demands of providing for too big a brood are a powerful incentive to limit your pairings to the female who will give you just a few strong young. For that reason, no sooner do we reach sexual maturity than we learn to look for signals of good genes and reproductive fitness in potential partners and, importantly, to display them ourselves. "Every living human is a descendant of a long line of successful maters," says David Buss, an evolutionary psychologist at the University of Texas at Austin. "We've adapted to pick certain types of mates and to fulfill the desires of the opposite sex." One of the most primal of those desires is that a possible partner smells right. Good smells and bad smells are fundamentally no different from each other; both are merely volatile molecules wafting off an object and providing some clue as to the thing that emitted them. Humans, like all animals, quickly learn to assign values to those scents, recognizing that, say, putrefying flesh can carry disease and thus recoiling from its smell and that warm cookies carry the promise of vanilla, sugar and butter and thus being drawn to them. Other humans carry telltale smells of their own, and those can affect us in equally powerful ways. The best-known illustration of the invisible influence of scent is the way the menstrual cycles of women who live communally tend to synchronize. In a state of nature, this is a very good idea. It's not in a tribe's or community's interests for one ovulating female to monopolize the reproductive attention of too many males. Better to have all the females become fertile at once and allow the fittest potential mates to compete with one another for them. But how does one female signal the rest? The answer is almost certainly smell. Pheromones — or scent- signaling chemicals — are known to exist among animals, and while scientists have had a hard time unraveling the pheromonal system in humans, they have isolated a few of the compounds. One type, known as driver pheromones, appears to affect the endocrine systems of others. Since the endocrine system plays a critical role in the timing of menstruation, there is at least a strong circumstantial case that the two are linked. "It's thought that there is a driver female who gives off something that changes the onset of menstruation in the other women," says chemist Charles Wysocki of the Monell Chemical Senses Center in Philadelphia. It's not just women who respond to such olfactory cues. One surprising study published last October in the journal Evolution and Human Behavior showed that strippers who are ovulating average $70 in tips per hour; those who are menstruating make $35; those who are not ovulating or menstruating make $50. Other studies suggest that men can react in more romantic ways to olfactory signals. In work conducted by Martie Haselton, an associate professor of psychology at UCLA, women report that when they're ovulating, their partners are more loving and attentive and, significantly, more jealous of other men. "The men are picking up on something in their partner's behavior that tells them to do more mate-guarding," Haselton says. Scent not only tells males which females are primed to conceive, but it also lets both sexes narrow their choices of potential partners. Among the constellation of genes that control the immune system are those known as the major histocompatibility complex (MHC), which influence tissue rejection. Conceive a child with a person whose MHC is too similar to your own, and the risk increases that the womb will expel the fetus. Find a partner with sufficiently different MHC, and you're likelier to carry a baby to term. Studies show that laboratory mice can smell too-similar MHC in the urine of other mice and will avoid mating with those individuals. In later work conducted at the University of Bern in Switzerland, human females were asked to smell T shirts worn by anonymous males and then pick which ones appealed to them. Time and again, they chose the ones worn by men with a safely different MHC. And if the smell of MHC isn't a deal maker or breaker, the taste is. Saliva also contains the compound, a fact that Haselton believes may partly explain the custom of kissing, particularly those protracted sessions that stop short of intercourse. "Kissing," she says simply, "might be a taste test." Precise as the MHC-detection system is, it can be confounded. One thing that throws us off the scent is the birth-control pill. Women who are on the Pill — which chemically simulates pregnancy — tend to choose wrong in the T-shirt test. When they discontinue the daily hormone dose, the protective smell mechanism kicks back in. "A colleague of mine wonders if the Pill may contribute to divorce," says Wysocki. "Women pick a husband Page 2 of 7Multi-Print Viewer 2/13/2008http://infoweb.newsbank.com/iw-search/we/InfoWeb the board-games-when-it's-raining phase, and the fact is, there's not a lick of excitement about it. But that, for better or worse, is adaptive too. If partners are going to stay together for the years of care that children require, they need a love that bonds them to each other but without the passion that would be a distraction. As early humans relied more on their brainpower to survive — and the dependency period of babies lengthened to allow for the necessary learning — companionate bonding probably became more pronounced. That's not to say that people can't stay in love or that those couples who say they still feel romantic after years of being together are imagining things. Aron has conducted fMRI studies of some of those stubbornly loving pairs, and initial results show that their brains indeed look very much like those of people newly in love, with all the right regions lighting up in all the right ways. "We wondered if they were really feeling these things," Aron says. "But it looks like this is really happening." These people, however, are the exceptions, and nearly all relationships must settle and cool. That's a hard truth, but it's a comforting one too. Long for the heat of early love if you want, but you'd have to pay for it with the solidity you've built over the years. "You've got to make a transition to a stabler state," says Barry McCarthy, a psychologist and sex therapist based in Washington. If love can be mundane, that's because sometimes it's meant to be. Calling something like love mundane, of course, is true only as far as it goes. Survival of a species is a ruthless and reductionist matter, but if staying alive were truly all it was about, might we not have arrived at ways to do it without joy — as we could have developed language without literature, rhythm without song, movement without dance? Romance may be nothing more than reproductive filigree, a bit of decoration that makes us want to perpetuate the species and ensures that we do it right. But nothing could convince a person in love that there isn't something more at work — and the fact is, none of us would want to be convinced. That's a nut science may never fully crack. [BOX] Liking What We See — and Hear We're suckers for a pretty face — and a lot more. Men prefer women with large breasts and a low waist-to-hip ratio, which are seen as signs of fertility. Women like men with muscular shoulders, a broad chest and a full beard. These are signs of strength and a healthy flow of virility-inducing testosterone. Men with deeper voices are perceived as having a high testosterone level and in one study were shown to have more children, suggesting that women respond to the way they sound. [BOX] The Lure of Smell Like all other animals, we respond to olfactory cues. The menstrual cycles of women living together often synchronize, something that is probably governed by scent. In the same way, men seem able to detect when women are ovulating — and thus are most fertile — and will behave more solicitously toward them during those times. Men and women respond to the scent of each other's MHC, part of the genetic makeup of the immune system and something that helps determine whether a fetus they might conceive will be carried to term. [BOX] When Love Dies Love is strong, but it's not indestructible. People who meet under the influence of alcohol or drugs or in a state of high excitement may cool off when their bodies return to baseline. Rejection may activate regions of the brain that control addiction, which is why it can be hard to quit someone even after that person has quit you. The spurned lover who grows angry or needy can push the other person even further away, which accelerates the split and may actually help both parties. [BOX] Why We Do It Nature doesn't really care if we experience the thrill of falling in love or not, but it deeply cares that we make a Page 5 of 7Multi-Print Viewer 2/13/2008http://infoweb.newsbank.com/iw-search/we/InfoWeb lot of babies and stick around to raise them. The problem is, human babies require an awful lot of care — 18 years or more. When we first reach sexual maturity, we scan the world for people to mate with. When we find someone, romance focuses that scattershot attention. Companionate love then bonds us to our partner for our child-rearing years and beyond. The Thermometer of Love You can't precisely measure love, but you can't deny that it comes in different temperatures: cool, hot and scalding. Three decades ago, psychologist Elaine Hatfield and sociologist Susan Sprecher devised the Passionate Love Scale, which remains in wide use today. Think of the person you love passionately now or someone you felt that way about in the past. Base your answer on when your feelings were most intense. For each of the 15 sentences below, choose a number from 1 (not at all true) to 9 (definitely true) that most accurately describes your feelings toward the person you love. Indicate your answer by circling the number in the corresponding row. 1. I would feel deep despair if _____ left me. 2. Sometimes I feel I can't control my thoughts; they are obsessively about _____. 3. I feel happy when I am doing something to make _____ happy. 4. I would rather be with _____ than anyone else. 5. I'd get jealous if I thought _____ were falling in love with someone else. 6. I yearn to know all about _____. 7. I want _____ physically, emotionally, mentally. 8. I have an endless appetite for affection from _____. 9. For me, _____ is the perfect romantic partner. 10. I sense my body responding when _____ touches me. 11. _____ always seems to be on my mind. 12. I want _____ to know me — my thoughts, fears and hopes. 13. I eagerly look for signs indicating _____'s desire for me. 14. I possess a powerful attraction for _____. 15. I get extremely depressed when things don't go right in my relationship with _____. ADD UP YOUR TOTAL Your score can range from a minimum of 15 to a maximum of 135. The higher your score, the more your feelings reflect passionate love; the items for which you picked a particularly high number indicate the components of passionate love you experience most [PULLQUOTE] When women are ovulating, they report that their mates are more loving and attentive and, significantly, more jealous of other men [PULLQUOTE] 'At the moment of a kiss, there's a rich exchange of postural, physical and chemical information.' Page 6 of 7Multi-Print Viewer 2/13/2008http://infoweb.newsbank.com/iw-search/we/InfoWeb --GORDON GALLUP, PSYCHOLOGIST, STATE UNIVERSITY OF NEW YORK [PULLQUOTE] 'Natural opioids get activated, and you think someone made you feel good, but it's your brain that made you feel good.' --JIM PFAUS, SEX RESEARCHER, CONCORDIA UNIVERSITY, MONTREAL [PULLQUOTE] The eventual goal of people who pair-bond is to move beyond the thrill of early love and into the comfort of the Sunday-paper-and-coffee phase Caption: FILM STILL: MGM — MPTV PHOTO ILLUSTRATION ILLUSTRATIONS BY SERGE BLOCH FOUR ILLUSTRATIONS Memo: Annual Mind & Body Special Issue See also 13 related articles on pages 53-100 of same issue. See also additional images in Cover Description file and Table of Contents of same issue. Edition: U.S. Edition Section: Cover Story The Science of Romance Page: 54 Volume: 171 Issue: 4 Index Terms: FEMALES ; SEXUALITY ; BRAIN ; SCIENCE ; SCIENTISTS ; POKER ; SEXUALLY TRANSMITTED DISEASES ; FERTILITY ; MALES ; BEHAVIOR ; Helen Fisher; COVER Record Number: 102977575 Copyright © Time Inc., 2008. All rights reserved. No part of this material may be duplicated or redisseminated without permission. Page 7 of 7Multi-Print Viewer 2/13/2008http://infoweb.newsbank.com/iw-search/we/InfoWeb