Women "Advertise" Fertility

Dik Zak writes with word of a paper published in the journal Hormones and Behavior. A study found that women take greater care over their appearance when they are at peak levels of monthly fertility. The researchers took two photos of each of 30 women, one near ovulation and one at the other end of her cycle. They then showed the paired photos (with faces obscured) to a group of observers, who were asked to judge in which photo the women were trying to look more attractive. The observers chose the "high fertility" subject nearly 60% more of the time than would be expected by chance.

Comments

Nothing for you to see here. Please move along.

[FST]

Looks like kdawson isn't too fertile right now.

What does this mean for men?

[atari2600]

Like you uhh know you we are (most of us) are at the 100% fertility rate most of the time and uhhh we don't care about advertising it. I am not sure where i am going with this. Oh snap, i need to shave the 4 month old beard. Wonder where dad keeps his razor...

Re:What does this mean for men?

[kalirion]

What it really means for men is that the more attracted you are the the woman you're having sex with, the greater the chances that you'll need to use protection.

Of course the only true way to be safe is to abs^H^H^Hread slashdot.

60% of 30?

[Scooter]

Hardly statistically significant:-

60% of 30 is 18 - I mean come on, that's only 3 over the pure chance 50%!

Re:60% of 30?

[Surt]

The article and summary are in disagreement. Choosing to assume the article is more likely to be right, it is 60% right guesses vs expected 50% right guesses.

However, also omitted from the summary is 42 guessers guessing on the 30 dress-up-women in the study. That's 42x30 guesses, with a 60% correct guess rate overall. 60% with more than a thousand sample points is well within the usual scientific standard for statistically significant.

Researchers should pay more attention

[Anonymous Coward]

There's a reason other than "randomness" that your wife bothers you more at times. It's not just because she thinks that you need "a break from your work". Open your eyes, men! She wants something from you!

My wife and I figured this out ages ago. She's all over me during ovulation. Anyone who's married and paying attention should also be able to notice this. But then again, how many guys know their wife's monthly schedule? Hmm.

--Posted as AC for privacy

Re:Researchers should pay more attention

[good soldier svejk]

Per my comment below, my wife and I have the inverse relationship. And I always know her schedule because if I find myself humping her leg, she is probably menstruating.

Re:Researchers should pay more attention

[PFI_Optix]

I learned something very early with my wife: when she hits ovulation, she's less interested me when I'm clean-cut and smelling good and all that and more interested in me when I haven't shaved, have been working outside all day, and am wearing some pretty rough-looking clothes.

The theory is that she goes for rugged-looking me because it makes me look stronger and tougher and so I look like a better choice for reproduction. "Strong man make strong babies" or something like that.

Knowing when she ovulates means knowing which days I can skip shaving and don't have to clean up before giving her a kiss after doing yardwork.

Re:Researchers should pay more attention

[doktor-hladnjak]

But then again, how many guys know their wife's monthly schedule?

Just another reason, I'm glad I'm gay.

Re:Researchers should pay more attention

[Rob T Firefly]

But then again, how many guys know their wife's monthly schedule?

I know your wife's monthly schedule.

Re:Researchers should pay more attention

[Anonymous Coward]

> Knowing when she ovulates means knowing which days I can skip shaving and don't have to clean up before giving her a kiss after doing yardwork.

I've heard cunnilinguis called a lot of things before, but "yardwork" wasn't one of 'em.

Until tonight.

My Evolutionary Disadvantage

[good soldier svejk]

According to my wife I have a genetic defect which causes me to be more attracted to her when she is menstruating. This has obvious disadvantages in that she is both unlikely to get pregnant and unlikely to not kick my ass when fondled in that state. Good thing I don't want kids, or a genetic legacy.

Women?

[suv4x4]

Dear stranger, what is this "women" you speak of?

Re:Women?

[Anonymous Coward]

google it. There are lots of web sites with pictures of them advertising their fertility.

Bad study

[G00F]

The case study was to small, only 30 women with only 2 pictures, not only did we not collect data, but with the lack of numbers we creates a very large error of margin.

Example, flip a coin once, and you get heads, your test reveals 100% heads when flipping a coin. Flip it 10 times, you got heads 3 times, so according to this test when flipping a coin you have 30% chance to get heads. Now flip it 100 times. That number will be a lot closer to 50%.

Try 1000 women with 6 pictures each (3 in prime and 3 out of prime) then have 100 different people scoring each card.

All this test does is shows is hey maybe there is something, and let us do a real test.

No, 60% more

[Chris Burke]

Not 60% of the time, but 60% more than expected if it were chance alone. So more likely 1.6 * (30*.5) = 24/30, not 18/30.

But of course the actual number isn't in the article.

Re:No, 60% more

[Surt]

The article is clear on this, the slashdot summary is wrong. It's 60% right guesses for 42 guessers against 30 pictures, over a thousand total guesses, with 60% right instead of 50% right.

Re:No, 60% more

[Surt]

30 is a low sample size, but would not be unusual in psychology studies. There are statistical tests you can perform to find out the minimum effect size to declare significance. I've seen studies with meaningful results in as few as 8 samples.

Nevertheless, this particular study had 1260 samples. 42 guessers * 30 guesses each. More than a thousand samples is plenty for significance.

Re:No, 60% more

[WilliamSChips]

42 judges. That number is important.

Re:No, 60% more

[Chris Burke]

Where the word 'more' came from, other than slashdot summary, I don't know.

It came from the New Scientist article which was linked from the summary at the end of the sentence: "The observers chose the "high fertility" subject nearly 60% more of the time than would be expected by chance, according to the NewScientist.com writeup."

So like I was saying, it isn't the slashdot summary, it's Daily Mall and New Scientist which are contradicting each other.

Thank goodness for the real study, though, which makes it clear that it is New Scientist which is incorrect.

Re:No, 60% more

[StikyPad]

Much more interesting is women's tendencies to forget to take birth control, and to have affairs during ovulation.

[W]hen women have sexual affairs with someone other than the husband or boyfriend, the affair often occurs during ovulation, the woman and her partner typically use no birth control, and the partner chosen by the woman has some quality that the husband/boyfriend lacks (Baker & Bellis, 1993; Bellis & Baker, 1990).

Re:No, 60% more

[EraseEraseMe]

the partner chosen by the woman has some quality that the husband/boyfriend lacks

Like a Porsche...

There's a reason for that

[ElleyKitten]

When I'm at "the other end of my cycle" aka, my period, I'm bleeding and bloated and cramping and my face is breaking out, and looking pretty is not exactly high on my list. When I'm not, looking pretty is much less of a hassle. So, not exactly rocket science here.

Re:There's a reason for that

[gfilion]

When I'm at "the other end of my cycle" aka, my period, I'm bleeding and bloated and cramping and my face is breaking out, and looking pretty is not exactly high on my list. When I'm not, looking pretty is much less of a hassle. So, not exactly rocket science here.

They did a similar study a while ago in a bar. They would ask female volunteers to give a saliva sample and have their picture taken. Then they calculated the area of the body that showed skin and found a correlation between "showing more skin" and ovulation. So it's likely more than just wanting to feel pretty, I mean you don't go in a bar if you feel "bloated and cramping". To me it looks like women are more horny why they are ovulating, which makes perfect sense if you think in terms of evolution.

Re:There's a reason for that

[Gospodin]

...which admittedly shouldn't surprise anyone who actually knows any women.

Ah. So that's why this made it as a news item on Slashdot.

FULL ARTICLE

[brian0918]

The full article can be found here.

False Advertising

[Anonymous Coward]

So they'll advertise, but never actually have any for sale? It's like shopping at Best Buy.

Re:False Advertising

[Rosco P. Coltrane]

So they'll advertise, but never actually have any for sale? It's like shopping at Best Buy.

No, when you buy something at Best Buy, you can return it if the product is defective.

My wife ways ...

[Tim Ward]

... "only years later did I work out that all my successful driving tests, interviews etc were at times when I was fertile".

About Statistical Significance

[flynt]

I am a statistician, and reading through the comments hear, am saddened that many readers claim that "statistical significance" could not have been achieved in this study because of a sample size of 30 women. First, that's only part of the random sample in this study, the other part is men sampled to judge the pictures.

Second of all, I have looked up the actual publication in "Hormones and Behavior", and the p-value associated with their main test is .01, which usually signifies statistical significance.

Ultimately, determining whether some difference in populations is due to chance depends on more than just sample size. It depends on how large of a difference you want to detect, and the variance of the measurements within a group. Of course, larger sample sizes help, but it ultimately depends on what you're studying, and the design of the experiment.

So while I definitely applaud being sceptical of all statistics, I urge you to look up the actual publications, read the methodology, and then decide if the results are something you believe. Kneejerk reactions to n = 30 don't really help anyone though.

I have not read through this publication in its entirety yet.

Re:About Statistical Significance

[Jerf]

I am a statistician, and reading through the comments hear, am saddened that many readers claim that "statistical significance" could not have been achieved in this study because of a sample size of 30 women.

I blame schooling for this. Not counting my actual statistics classes, whenever I was asked to criticize a paper I always got credit for complaining that the sample size was too small, even when I knew I was completely full of shit and even when the various measurements of significance were sitting right there in the paper.

All you've got is the lone statistics course fighting even the other professors at a University, who apparently apply the statistical significance tests by rote, but don't really "believe" in them (or understand them to any degree). It's not hard to guess which will "win".

"who did not know what the study was about"

[exp(pi*sqrt(163))]

Doc: Thank you for volunteering for our experiment
Subject: That's fine. What's it about?
Doc: We can't tell you. But could you tell me what part of your menstrual cycle you're in?
Subject: So it's about menstrual cycles?
Doc: No. We ask everyone that quaestion.
Subject: I believe you.

Partial article text from ScienceDirect

[shrubya]

To put this matter to rest, here are some relevant paragraphs of article text (thank you, worldwide university subscription):

Method
Procedure: photographic stimuli

Thirty women from the UCLA campus (mean age = 21.07 years old; SD = 2.35; range 18-37) posed for two standing full-body digital photographs with their hands placed at their sides (Canon PowerShot S410, 4.0 Megapixels). Women identified themselves as African American (n = 1), Asian American (n = 10), Caucasian (n = 6), Hispanic/Latino (n = 7), and mixed race or "other" (n = 6). One photograph was taken on a high fertility day of the cycle (follicular phase) and one on a low fertility day of the cycle (luteal phase). Photographs were taken in the same location under standardized lighting conditions against a plain blue background. All women reported regular menstrual cycles (ranging between 26 and 35 days), were partnered (involved in a "committed romantic relationship" with a man), and none had used oral or other hormonal contraceptives within the last three months. Because previous studies have found stronger ovulatory effects in partnered than in non-partnered women (e.g., Havlicek et al., 2005 and Pillsworth et al., 2004), we limited our investigation to partnered women.

Session scheduling and luteinizing hormone (LH) testing were conducted using the procedures described in Gangestad et al. (2002). There were three sessions--an initial session for cycle history assessment and scheduling and subsequent high and low fertility sessions. After initial sessions, women were scheduled to return for the next possible session (low or high) given their current cycle day. Low fertility sessions were scheduled to occur 4-10 days prior to the estimated day of next menstrual onset. Actual menstrual onset was reported by 66.7% of women after their low fertility session; for the balance of participants, menstrual onset was estimated using cycle length and the last date of menstrual onset. On average, based on these information sources, low fertility sessions took place 5.87 days prior to menses (SD = 2.5; three women participated within 48 h of menstrual onset and possibly could have experienced premenstrual symptoms; therefore, days-to-menstrual-onset is included in the analyses presented below). High fertility sessions were scheduled to occur 15-17 days prior to the next estimated menstrual onset. Participants also reported to the laboratory to complete urine tests beginning two days prior to their high fertility session and continuing for three days after this session or until an LH surge was detected. Using an unmarked commercially available urinary stick ovulation test (Clearblue(TM)), all women were judged to have an LH surge between three days after and two days before their high fertility session. An LH surge typically proceeds ovulation by 24-48 h (Guermandi et al., 2001); thus, all women were likely to be near ovulation during their high fertility session. Within the fertile window of the cycle, conception risk increases as ovulation approaches (Wilcox et al., 1995). We therefore estimated days-to-ovulation (by adding two to days-to-LH surge; mean = 3.03, SD = 1.40) and included this estimate in the analyses reported below.

These 30 women were a subset of 58 originally recruited for the study. Women ineligible for inclusion in the study either showed no evidence of an LH surge (n = 4), were rescheduled for low fertility sessions (due to their own time constraints) on days falling outside of the range of the luteal phase days (n = 3), did not consent to having photos taken (n = 7), consented to having their photos taken but did not consent to having their photos judged by people other than the researchers (n = 7), or did not complete all sessions (n = 7). There were no significant differences in relationship satisfaction, sociosexuality (Simpson and Gangestad, 1991), age, or relationship length between women retained in the study and those who were ineligible.

Participants were blind to the purpose of the stu

It means...

[Anonymous Coward]

This is the one type of advertising where you don't want your pop-up to be blocked.

Re:Yes but

[bcattwoo]

does it really mean anything for us humans? I mean, if women actually attracted more men when they look attractive, then we wouldn't have had a surge of babies 9 months after the northeast power blackout, quite the contrary.
Sure we would. Everyone looks better in the dark.

Can I take your picture?

[Anonymous Coward]

What woman in her right mind would allow someone to take photos of her based on her freakin' period?

"Will you be menstrating in the next week?"

*smack*

"I take that as a yes."

Re:Not statistically independent, however

[aethogamous]

For sake of argument, assume that there is an objective way to measure who takes greater care of their appearance and that all 42 judges are experts at measuring that and never wrong. In that case, these results boil down to 18 out of 30 women taking better care of their appearances during one of their ovulation phases than during one of their non-ovulation phases. When you combine that with the possibility that some of the judges could be wrong (thus increasing the expected variance), it's even less significant - not more. I'm going to go with Scooter on this one.

The published analysis is more analogous to saying that each women has a score that measures how much more or less attractively they dress during ovulation. In the article's case the score is defined in terms of the percentage of observers who think that a women is more attractively dressed during ovulation, with scores ranging from 0% to 100%. The 42 observers are used to estimate that score for each women. The reported percentage of 59.5% is the mean of these scores, and is not a percentage of the 30 women.

The analysis asks whether this mean score is greater than 50%. Whether or not significance is achieved with 30 observations in this case depends on the distribution of these 30 scores, which is not given in the article. Using only the information about the mean (59.5%), using a t.test (the actual analysis was more sophisticated, and included covariates) we can easily constuct p-values ranging from 0.1404 (12 women score 0%, 18 score 100%) to 5.969e-12 (15 women score 55%, 15 women score 65%)

It is possible (but presumably unlikely) that more women actually looked worse to a majority of the observers during ovulation and still get a mean score of 65% (for example if 22 women scored 45% and 8 scored 100%).

Be careful

[Anonymous Coward]

When you allow a plug-in root access, there's always risk of spawning child processes.

Re:NS article is missing a comma

[uhlume]

In other words, having missed the comma, the NS article suggests a higher probability of a missed period?

Moderators: parent post is GARBAGE!

[Tim]

Moderators, for the love of....don't just give high ratings to people who post technical-sounding gibberish!!

The parent post is spreading misinformation with regard to the link between libido and di-hydro-testosterone (you'll note that he got the abbreviation incorrect, and attached a spurious "5a" to the front, because he confused the name of the enzyme -- 5-alpha-reductase -- responsible for DHT formation with the chemical itself!)

I'm not going to claim that DHT isn't involved with male sex drive, but it's certainly not the "primary mechanism" behind male libido. One needs only refer to the volumes of studies done on the relationship between selective serotonin reuptake inhibior antidepressants ("SSRIs", e.g. Celexa, Prozac, Paxil) and libido suppression to see that the issue is more complicated than a single hormone imbalance.

What makes this really galling, however, is that the guy has the guts to criticize real scientific research before spouting this crap, and you folks take it as some sort of authority!

Why slashdot postings can be terrible...

[bogd]

but not directly caused by ovulation itself. The underlying reason is progestogen.

Who said it was caused by the ovulation itself? The article was just saying that women tend to dress more attractively when they are fertile. Whether that is caused by the ovulation itself, by progesterone, or random firings of the synapses is something that we still don't know. progesterone is used in the final stages of ovulation

1) Please stop mixing up progesterone (the natural hormone) with progestogen (class of hormones) and progestin (synthetic hormone).

2) Take a look here. You will see the evolution of hormone concentrations over the course of the menstrual cycle. If what you are saying was true (and the effect mentioned in the paper really was caused by the progesterone), you would expect to see an increased effect when progesterone levels hit their peak - somewhere in the middle of the luteal phase. (and no, that is not "in the final stages of ovulation")

But let's look at the article again:

[the photos were taken] one on a high fertility day of the cycle (follicular phase) and one on a low fertility day of the cycle (luteal phase).

What do you know? Those days in the luteal phase are actually low fertility days. Days in which women don't care as much how they look. Precisely the opposite of what you were saying...

Also, I don't understand what the second paragraph (the one about DHT) has to do with anything. It's not related to the article, it's not related to the other paragraphs in your post, and it's also wrong. Have a look here - mesterolone (the active ingredient in Proviron) is not hydrogenated - so it is a relative of testosterone, rather than DHT (compare it with the images found here).

The conclusion? You don't know what you are talking about, but you go around criticizing other people's research. The fact that your post got a "+5, informative" modifier only proves that people will believe anything that sounds technical, even if it's pure garbage...