Monday, February 11, 2008

The Science of Love: Good News/Bad News

The Bad News - The Truth About Prairie Voles

Prairie voles might once have been thought suitable mascots for the romance genre, because, although "Fewer than 5% of mammals are habitually monogamous. Prairie voles (Microtus ochrogaster) are among the select few. After mating, the males "fall in love": they stick close to their chosen one, guard her jealously and help her raise their young." (BBC). Or so everyone thought. Now it turns out that
"monogamous" prairie voles are really just a bunch of randy rodents. A study published in Animal Behaviour found the prairie vole, Microtus ochrogaster, displayed considerable sexual promiscuity. Almost a quarter of litters were found not to have been fathered by the live-in partner of the mother prairie vole.

"There is a difference between social monogamy and sexual fidelity," said the study's main researcher, Professor Alex Ophir, of Florida University, Gainesville. "You can pair with a partner for life and still have sex with others - and that is what prairie voles do. There is a lesson there for humans."

The discovery of prairie vole promiscuity is crucial because these animals are favourite subjects among researchers, selected because they had displayed life-long monogamy. These previous studies also showed that dopamine, a brain chemical released during sex, played a key role in determining vole sexual behaviour.

Dopamine - the vole's love drug - causes males to lose interest in other females and acts on the nucleus accumbens, a region in the forebrain of many animals, including humans. Previous studies claimed dopamine locked the vole into monogamy and, by inference, played a similar role in humans - an idea that promised new ways of understanding, and possibly treating, serial promiscuity. (McKie, in The Observer)

The Good News - Romance Authors are Right to Mention the Hero's Smell

I've been noticing that the hero's smell is often mentioned in romances. The description often goes something like this: "he smelled slightly of horse, soap and a scent that was uniquely his." And it seems that smell, particularly the one that's "uniquely his," is important in mate choice:
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.

[...] 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. (Kluger, in Time)
And in addition, to paraphrase the lyrics of Betty Everett's "It's In His Kiss" just a little, "if you wanna know, if his MHC is different from yours, it's in his kiss, that's where it is":
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." (Kluger, in Time)

There's even a scientific basis for all those couples in romantic suspense who fall in love really quickly:
Meeting a stranger when physiologically aroused increases the chance of having romantic feelings towards them ... It's all because of a strong connection between anxiety, arousal and attraction. In the "shaky bridge study" carried out by psychologists Arthur Aron and Don Dutton in the 1970s, men who met a woman on a high, rickety bridge found the encounter sexier and more romantic than those who met her on a low, stable one. (Case, in New Scientist)

The Bad News - HEA may turn to Increasing Irritation

The initial glow of falling in love tends to wear off, as described in detail in Kate Nash's "Foundations" (lyrics here, and video and song here), and:
If your spouse already bugs you now, the future is bleak. New research suggests couples view one another as even more irritating and demanding the longer they are together. [...] [Kira] Birditt and U-M colleagues Lisa Jackey and Toni Antonucci looked at how negative views of spouses, friends and children changed over time [...] In all age groups, individuals reported viewing their spouse as the most negative compared with children and friends. The negative view of spouses tended to increase over time. (MSNBC)
Psychologists studying relationships confirm the steady decline of romantic love. Each year, according to surveys, the average couple loses a little spark. One sociological study of marital satisfaction at the University of Nebraska-Lincoln and Penn State University kept track of more than 2,000 married people over 17 years. Average marital happiness fell sharply in the first 10 years, then entered a slow decline. (Schechner, in the Wall Street Journal)

The Good News - True Love Can Last

For some people, however, that initial glow never fades: there are
men and women who say they live in the thrall of early love despite years of marriage, busy jobs and other daily demands that normally chip away at passion. Most couples find that the dizzying, almost-narcotic feeling of early love gives way to a calmer bond. Now, researchers are using laboratory science to investigate [...those] who live fairy-tale romances. (Schechner, in the Wall Street Journal)
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." (Kluger, in Time)
For more on the science of love, RfP's got an index of Time's annual Mind/Body special issue on the theme of "The Science of Romance".

Other News

Harlequin's Valentine's site is now up and there are free short online reads available: an inspirational romance, Family Ever After, by Linda Goodnight, and a vampire paranormal, Desire Calls, by Caridad Piñeiro.

The RNA 2008 Romance Prize for category romances was won by Kate Hardy's Breakfast at Giovanni's. It'll be out in the US in April, with the title In Bed with her Italian Boss.

AAR's Annual Reader Poll closes on the 17th of February 2008. Only novels with a "first US publication date (copyright date) of 2007" are eligible. Laurie Gold has clarified that readers who don't usually visit AAR are eligible to vote: "we want more than simply AAR’s readership involved; we want to draw from the entire community of online romance readers."

The first illustration, from Wikipedia, is of the "theatrical masks of Tragedy and Comedy in refined mosaic" originally from Hadrian's Villa and now at the Capitoline Museums, Rome.

The second illustration is of Harlequin, from Wikimedia Commons.


  1. I say we feed those prairie vole bastards to the black-footed ferrets!

    Please note that that's Vole-with-a-V and not Mole!

    As I recall, Dr. Tatiana said that in the animal kingdom, taken as a whole, monogamy is a rare perversion. It's certainly counter-evolutionary if you buy the "a hen is an egg's way of making another egg" theory.

    As for scent, there are now perfumes sold on the basis that they will enhance one's natural pheromones.

  2. Unfortunately, women on birth control don't seem to detect the histocompatibility complex reliably--they choose men with the wrong-smelling T-shirts.

    There's also a Scientific American article on the science of kissing. I didn't post on it because there's a *lot* of argument about what it all means.

    There's a lot of debate over whether humans detect pheromones per se. The Pure Pedantry science blog has a number of the references--including the Sci. Am. article.

  3. As I recall, Dr. Tatiana said that in the animal kingdom, taken as a whole, monogamy is a rare perversion.

    Yes, I suppose I shouldn't have been so surprised. But some of the earlier reports about the promiscuous mountain voles and the supposedly monogamous prairie voles really played up the difference between the two species.

    As for scent, there are now perfumes sold on the basis that they will enhance one's natural pheromones.

    I'm not sure about all the ones which are commercially available, but the concept itself has been tested (I don't know if the findings were replicated in subsequent tests, or even if there have been subsequent tests):

    Some perfume manufacturers claim to include pheromones in their fragrances, McCoy noted, but “few double-blind placebo controlled studies have been conducted on this subject.” The Athena Institute for Women’s Wellness in Chester Springs, Pa. produced the pheromone used by the SFSU researchers.


    The study, the first of its kind to independently test a sex attractant pheromone for women, showed that of the 36 women tested, 74 percent of those wearing their regular perfume with the pheromone saw an overall increase in three or more of the following sociosexual behaviors: frequency of kissing, heavy petting and affection, sexual intercourse, sleeping next to their partner, and formal dates with men.

    In contrast, only 23 percent of the women who had a placebo added to their perfume saw an increase in these sociosexual behaviors. Researchers conclude from these data that the pheromone users were more sexually attractive to men.
    (from here)

    Thanks for the article about kissing, RfP. I'm sure you're right that one can overstate the importance of some of these things, and humans obviously do take into account a lot of different cues. But it's interesting how much we may be affected by our hormones, even though we think we're in control, and in that respect it's interesting that being on the pill, as you say, or in a dangerous situation, can temporarily affect our perceptions of attractiveness/mate suitability.

  4. it's interesting how much we may be affected by our hormones, even though we think we're in control

    Yes--I didn't mean to downplay that. We are still animals, though we lack some of the more sensitive adaptations to hormonal/pheromonal cues.

  5. '...women on birth control don't seem to detect the histocompatibility complex reliably--'

    Presumably because oral contraception (which I take you to mean) suppresses ovulation in part by mimicking the hormone balance of pregnancy - and if a female is already pregnant, she is not actively searching for a mate at that moment.

  6. Yes, that's right, Tigress. Apparently the scientists in Bern weren't expecting that outcome:

    That women using the Pill should opt for men with similar MHC genes, however, was a surprise.

    Wedekind is still mystified by this result. But he explains that the balance of hormones circulating in the blood of women taking oral contraceptives is similar to that in pregnant women.

    During pregnancy, very different factors may influence a woman's odour preferences. Pregnant women should be less concerned with selecting men who could provide suitable genes for their offspring, as they are unable to conceive. But during human evolution, it may have been useful for a pregnant woman to associate with men who were most likely to help care for her baby. They would have been close relatives, with MHC genes similar to the woman's own.