From Friday’s BBC Science in Action podcast is more on the biology of love. According to research presented by Lucy Vincent (neurobiologist at the French Scientific Research Center) and Dave Perrett (Professor of Psychology at the University of St. Andrews), one of the many factors that stimulate attraction and feelings of deep affection is the hormone oxytocin, more specifically the density and activity of oxytocin receptors. Okay, so that much has been known for years. However, Dr. Vincent goes on to say that these oxytocin receptors are very prevalent only for about three years in humans. Not only that, but as the oxytocin receptors become less dense and/or functional, receptors for vasopressin seem to take over, producing more of an “enemy” response rather than affection (though she admits the “enemy” thing is a substantial extrapolation).
According to the good doctors, this seems to fit with evolutionary pressure derived from the extreme vulnerability of human infants, which require(d) two parents to take care of and protect them full-time. However, after 12-18 months the infant becomes significantly less vulnerable (able to stand and perhaps throw off a bird or small animal attacking it), at which point only one parent would be necessary. And at that point, the oxytocin effect more or less ceases, yielding to increased vasopressin receptor activity- essentially a biochemical foundation for why people tend to “fall out of love” after a few years. Pretty heavy.
Professor Perrett adds that strong parent-child bonds tend to be transgenerational, and that many girls from families without strong bonds not only reach puberty earlier, have less stable relationships, and marry and bear children earlier, but also tend to have less dense oxytocin receptors.
Both researchers agreed that, while potentially a big downer, it’s certainly better to know what’s going on up there. Or at least, to know there’s a biochemical basis for why love wanes and it’s not all like “Oh crap, i’ve made a huge mistake.”
I wasn’t able to find any actual articles on this, just the BBC podcast so if any of y’all stumble across one, send it my way.
March 20, 2008 at 2:18 pm
I attended a seminar on human relationships once and it was really interesting stuff. I’ve always wondered to what degree the psychological aspects of mate choice (familiarity leading to an increased perception of attractiveness, building emotional ties, etc.) prior to childbirth help to balance these more physical, instinctive bonds we have that start to dissipate after we’ve been confronted with said young themselves. Lots of marriages have a rocky patch after about 5 years, they say, but recently that has left a spate of 2 and 3-year olds with divorced parents. Maybe recognizing that predictable natural slump is normal would help couples weather it.
March 21, 2008 at 10:18 am
Ow…
I’m curious about the mechanisms underlying the neuropsychological of it, also how it’s affecting the brain-physiological development of emotion and behavior.
Can we do the research of it in the rat?
Hah!! It will be interesting.
Hey, I’ll put your to my bloglink, ok?
Thank you so much.
March 21, 2008 at 11:44 am
That’s exactly what i’m thinking, and i think what the authors/presenters were getting at. Inject a little bit of rationality into something generally viewed as completely irrational, hopefully it would help.
March 21, 2008 at 12:46 pm
Very interesting. I was researching unrequited love (limerence), and found that the accumulated data on that “psychological problem” shows that those feelings last about three years. (Tennov, 1979, estimates, based on both questionnaire & interview data, that the average limerent reaction duration, from the moment of initiation until a feeling of neutrality is reached, is approximately 3 years).
March 21, 2008 at 1:07 pm
This blog is profound. Essentially, if one was to ponder over the the psychological aspects of mate selection then, one may whine up pondering over the nature vs. nuture controvesy and how it effects attraction. Talk about opening pandora’s box.
When at the end of the day, it all boils down to the fact love has no rhyme and reason nor is it a pefect science.
March 22, 2008 at 12:59 pm
[…] en Ciencia, Varios by sonicando on Marzo 22nd, 2008 No os perdáis el siguiente artículo…BIOCHEMISTRY IS LOVE.. de otro bloggero de la casa […]
March 22, 2008 at 1:44 pm
Quizás, uno debe seguir sus el propios aconseja.
March 24, 2008 at 1:06 pm
Well, I can’t find that podcast anywhere and would really like to listen to it. The BBC doesn’t seem to archive their podcasts. Got a better link?
March 24, 2008 at 2:38 pm
Susan (and anyone else interested),
Kinda lame they don’t archive the podcasts, isn’t it? I couldn’t find another link but the .mp3 hadn’t been auto-deleted from my iTunes yet, so if you want i’d be happy to send it to you (it’s a little over 12MB).
March 26, 2008 at 8:35 am
that would be excellent. Can you see my email? Hopefully I can find yours and will email you.
March 26, 2008 at 8:36 am
well, it’s susan at kuchinskas dot com
March 31, 2008 at 9:00 pm
I think Vincent is conflating and misrepresenting a lot of science, as well as different modes of relationship. Romantic attraction is different from committed love, and according to the work of Helen Fisher, it employs different areas of the brain and different neurochemicals.
See http://www.hugthemonkey.com/2007/12/get-over-romanc.html for more.
The oxytocin bond definitely does not dissipate after two or three years; the motivational state of lust and attraction known as romantic love seems to, according to the work of Donatella Marizziti.
As to the amygdala’s receptor set changing from oxytocin to vasopressin, thereby turning a lover into an enemy, that’s just plain wrong. Vasopressin seems to be involved in male bonding, when it stimulates protective behaviors like guarding the nest and the mate.
As far as I can tell, Vincent hasn’t actually done any work in this area herself.
Perrett, who didn’t get to say much, is an expert on attraction. He hasn’t done any work on receptor expression himself, but he is closer to right when he says that your family environment influences bonding. In fact, early nurturing influences the expression of many genes, including those for the distribution and sensitivity of oxytocin receptors.
How did these two get this gig, I wonder?
April 2, 2008 at 1:41 pm
Thanks for the corrections, Susan! Very interesting, indeed. Perhaps that’s why they don’t appear to have published anything on it?
April 2, 2008 at 9:45 pm
[…] Susan over at Hug the Monkey, a great blog about oxytocin, for pretty much completely refuting my last post about oxytocin and love. Looks like there may be a good reason i couldn’t find anything the […]