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Jun 5, 2009 11:50 AM | 22
FULLERTON, CALIF.—If you want to wait by the phone for your next college-aged daughter's call home, you should mark the days of her menstrual cycle on your calendar.
Well, not exactly. But that was one reasonable conclusion of research presented here last week at the 21st annual conference of the Human Behavior and Evolution Society (HBES) at California State University, Fullerton, by Elizabeth Pillsworth, a graduate student in Martie Haselton's lab at the University of California, Los Angeles.
Haselton (pictured at left with David Buss of the University of Texas at Austin) studies sexual attraction, relationships, and how fertility cycles influence mate preferences and choices (for instance, women dress in a more sexually provocative manner during the high fertility phase of the month). In an interesting twist on this body of research, Pillsworth studied the effects of the fertility phase in women on the incest taboo—specifically, how often college-aged women phoned their dads (versus their moms) during the month. Wow. It never ceases to amaze me how clever scientists can be in thinking up new research paradigms: Who would have ever thought of correlating cell phone calls with estrus cycles? Pillsworth and Haselton (and their colleague Debra Lieberman) did! And the results were most revealing.
But first, some background. On the 200th anniversary of Darwin's birth and the 150th anniversary of the publication of The Origin of Species, Darwinian principles have finally come online in mainstream psychology. HBES is the official organization of evolutionary psychologists and a champion of applying Darwinian thinking to human psychology, and its conferences seem to be gaining steam. The last HBES meeting I attended was at the University of California, Santa Barbara, in 1995, and it was sparsely attended. This year, 450-plus attendees packed the tiny conference rooms.
Now to Pillsworth's research: Kin affiliation in evolution is critical for predator avoidance, food procurement and sharing, protection from the elements, and so on. That is, being in a family group is extremely important for mammals. But there is an equally important downside: inbreeding. If you mate with people who are genetically similar to you, there are consequences: higher rates of infant mortality, deformed sperm, sterility, and genetic defects of all sorts—think hemophilia in the royal families of Europe in the 19th and early 20th centuries. Research shows that the offspring of first cousins are twice as likely to suffer congenital malformation and genetic disease and face up to a 5 percent increase in mortality; the offspring of siblings show a 45 percent increased risk of mortality.
Thus, mammals evolved numerous adaptations for inbreeding avoidance: dispersal from natal groups (usually sex-biased), kin recognition and avoidance, and a preference for extra-pair or extra-group copulations rather than copulating within one's group. Pillsworth cited a study on horses that found that mares only leave their group temporarily to join other breeding groups. So there is a conflict of wanting to be close to your kin and kind, but not too close.
The researchers' hypothesis on incest avoidance was that near ovulation, women are motivated to avoid affiliation with male kin (fathers) but not mothers, to avoid the potential costs of inbreeding. Their predictions were that relative to low-fertility days, on high-fertility days women would initiate fewer calls and engage in shorter conversations with fathers, compared to mothers.
They had 51 normally-ovulating women (mean age 19.1 years old) provide complete cell phone bills from one month, along with their menstrual cycle information and details about individuals on their phone bill. It turned out that the subjects called their fathers significantly less than their mothers during high fertility days, and when both mothers and fathers called them during high fertility days they spent less time on the phone with their dads than with their moms.
Conclusion: "this is the first evidence of adaptation in human females to avoid affiliation with male kin when fertility is at its highest."
This study was of particular interest to me because I have a 17-year-old daughter who will be going off to college in a little over a year. Like most parents, I am dreading the day she is gone, when I'll lose my daily contact with her, and am hoping that she calls regularly. I guess I will have to make a mental note of her high-fertility days and expect fewer calls from her—but being that I'm her dad, that won't stop me from calling her and stalling on the phone just to mess with her evolved psychology! Of course, an alternative explanation is that we dads tend to be a bit controlling on matters of our daughters and the boys that love them, and so perhaps daughters avoid talking to their dads during those high-fertility days when they are more inclined to, well, you know ... do things that we dads don't want them to. So instead of “incest avoidance,” an alternative hypothesis might be “controlling dad avoidance.”
Photo of evolutionary psychologists David Buss (left) and Martie Haselton (right) at the HBES conference: Michael Shermer
Tags:
evolutionary psychology,
HBES conference,
evolution
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22 Comments
Add CommentThat has to be the worst opening paragraph I've ever read.
Reply | Report Abuse | Link to thisScience in motion; gotta love it! What's more it's evolution in motion; gotta love what others hate. I'm pleased as punch.
Reply | Report Abuse | Link to this@hotblack: it caught your attention though.
Reply | Report Abuse | Link to thisI thought this would go in the opposite direction at first because "the results were most revealing."
The subject matter of the conversation will be effected by someone's physical and emotional state. and may have nothing to do with considerations of incest, especially if the subject matter is of more interest to a woman (mother) than a man (father). Daughters discuss their feelings during menstrual periods almost exclusively with other women.
Reply | Report Abuse | Link to thisThere's also the embarrassment factor, etc., etc., etc. Evo psych is an "scientific" enterprise.
What I actually wrote above was that evo psych was an all hat no cattle "scientific" enterprise.
Reply | Report Abuse | Link to thisA follow up could be to do the same trial on a group of daughters who are on the oral contraceptive pill, who do not ovulate and who have artificial levels of hormones.
Reply | Report Abuse | Link to thisIf the hypothesis is correct there should be a difference between this latter group and those in the study
That would be getting a bit too close to doing real science.
Reply | Report Abuse | Link to thisthey're basing their conclusions on information provided by 51 women for ONE MONTH?? sorry, but that's not science...
Reply | Report Abuse | Link to this"What I actually wrote above was that evo psych was an all hat no cattle "scientific" enterprise."
Reply | Report Abuse | Link to thisroyniles: You're not saying that when the well is durned near dry as a squirrel's hoof the mares in the north forty won't be grazing on no spring barley till spring comes in October? Speak English, man. This is a science thread.
The study was done in Texas. Nuff said?
Reply | Report Abuse | Link to thisI hate this, and I hate that it does explain puzzling variations in behavior. There's such a thing as too much information. Well this is a forum for science. Unfortunately the data on 50 subjects is not conclusive, so it seems we're going to be hearing more about this again.
Reply | Report Abuse | Link to this"Daughters discuss their feelings during menstrual periods almost exclusively with other women.
Reply | Report Abuse | Link to thisThere's also the embarrassment factor ...""royniles"
Fyi roy: The study was related to the menstrual cycle, not menstruation per se. Actually it was more concerned with their fertile period, not their "menstrual period."
If the embarassment factor did play a part it would have more caused by having to chat with dad when feeling horny. But feeling horny probably wouldn't cause embarssment, it would just make dear old dad seem about as interesting as a bump on a log.
You're entitled to your opinion, but substituting opinion for scientific examination is what gets evo psych people their reputation as being little more than neo behaviorists.
Reply | Report Abuse | Link to thisWow, some people really hate hearing about unconscious behaviour patterns. I bet they get a heart attack just thinking about their heart beating without them telling it to.
Reply | Report Abuse | Link to thisOr thinking happening without them ordering a thought to be thunk. Or seeing, or hearing. Whatever.
But of course, reproductive and kin behaviour is culturally determined. Says "our" current culture.
Naturam expellas furca, tamen usque recurret...
I agree with udrgrndgril and ralph skinner above. This is much too small a sample size and time period for strong conclusions. And comparisons with a control group using the pill would be useful. When the experiment was first being explained, I thought the period of time would be at least a semester. I suppose budgetary considerations kept this very small. Now that there is some indication of possible validity, how about a better study?
Reply | Report Abuse | Link to thisThe problem with evolutionary psychologists is that they don't think! They are simply too busy making up "just so" stories!
Reply | Report Abuse | Link to thisThe problem with evolutionary psychologists is that they don't think. They are simply too busy making up "just so" stories!
Reply | Report Abuse | Link to thisno, 50 women / one month are not enuf. can they wait for at least a thousand femme and one year to get to the conclusions?
Reply | Report Abuse | Link to thissecondly they can also study at the same time the opposite phenomena of attraction between kith during and beyond the unsafe period of the cycle.
Reply | Report Abuse | Link to thisOR--if you want to know when your daughter might call, you could try calling her. There's no government funding required to figure that one out.
Reply | Report Abuse | Link to thisI now partially understand why Million Dollar Baby got oscar for best movie and the kind of reactive attachment we all have with our parents. But what is the solution. I think our parents need us in our old age.
Reply | Report Abuse | Link to thisThis study is indeed true but against of what the author had stated, I will not wait or supervise with her menstrual cycle. As a parent, I will do my duties of what must have to do.
Reply | Report Abuse | Link to this<a href="http://www.stirling-manor.com/conference-venue.html/"><b>conference venue</b></a>