Tuesday, October 16, 2012

Study finds that women with severe endometriosis are more attractive

Researchers in Italy recently published a study in the journal of Fertility and Sterility on the relationship between a severe form of endometriosis and overall attractiveness. Endometriosis occurs when the uterine lining grows outside the uterus. The tissues will thicken and shrink just as normal uterine cells do during a woman's monthly cycle. These fluctuations can be extremely painful and eventually lead to infertility.

The study found that women who have severe endometriosis tend to be more attractive as compared to those with a milder form or without the condition.To conduct the study, the researchers rated the overall attractiveness of women with a severe form of endometriosis using a 5-point scale. They also calculated their Body Mass Index (BMI), and took measurements of their breast size and hip-to-waist ratios, all key indicators of attractiveness in women.

Why would more attractive women be more susceptible to severe endometriosis? The researchers suggest that estrogen plays a key role. As stated earlier, female attractiveness is linked to higher estrogen levels, so the condition "might favor the development of aggressive and infiltrating endometriotic lesions, particularly in the most feminine subjects."

After thinking a lot about evolution's role in shaping women today, I started to wonder what evolutionary purpose attractiveness serves, especially if this could ultimately result in infertility through endometriosis.

First off, what does it mean to be attractive? According to evolutionary psychology, attractiveness is perceived when an individual has symmetrical features. Research has consistently shown that humans have a strong preference for symmetrical faces.

Additionally, attractiveness is determined by sex hormones: estrogen in women and testosterone in men. The higher the levels of these sex hormones, the more attractive one is perceived to be. For example, higher levels of estrogen direct fat deposits to women's lips, hips and breasts, features that are found attractive to heterosexual men.

These female features, combined with bodily symmetry, indicate that someone is in good health and is likely fertile. Women with these traits are preferred because they are more likely to produce offspring that will have a greater chance of survival. Features with less symmetry suggest mutations or the presence of toxins, and are not ideal for reproduction. So, it seems, nature has created attractiveness to signal to mates who would produce the healthiest offspring.

Research published in Reproductive Sciences has shown that attractive women are more likely to have daughters than sons. Since attractive women are preferred as mates and are having more daughters, over evolutionary history, women will gradually become more attractive and more numerous than men. A study by a researcher at the University of Helsinki found similar results, but also suggested that attractive women have a greater number of children overall than their less attractive counterparts.

So why would evolution both favor and disfavor attractive women? Why would evolution favor attractive women for reproduction, while at the same time making them more susceptible to a disease that causes infertility? Perhaps the environment and technology are changing our physiology faster than evolution can keep up with.

Although attractive women are still favored by men, this may be changing as plastic surgery and other techniques allow women to change their appearance (presumably to make themselves more attractive). Women who choose to undergo procedures that make them more attractive, however, will not become more fertile as result: they do not have the underlying genetics that dictate attractiveness.

With regard to endometriosis, research suggests that environmental toxins play a role in its occurrence. This may account for the contradiction between attractiveness making a woman fertile while simultaneously making her prone to a disease that takes it away. Although attractiveness is still likely a positive sign for the health of a woman, the environment and modern technology may trick evolution, rendering an attractive woman not necessarily a healthy or fertile one.


Sarah said...

This is so interesting! I was really struck by what makes more attractive women have more children. Are they more likely to find mates? Feel more invested in passing on their good genes? They are more likely to have daughters and therefore keep breeding to produce a desired son? So fascinating. Thanks for sharing.

MC said...

CET, I absolutely loved this post. I appreciate the scientific qualification of “attractive,” as well as the evolutionary framework used to describe the interplay between attractiveness and health. Given the width of my hips, I’ve been told by many of my doctors that I’m going to have healthy babies. The common follow up question is whether I’ve had any reproductive health issues. This post puts it all into perspective.

While reading this post I became curious about how this correlation works for men. It seems that studies indicate that females prefer male faces that have sharp lines. Moreover, men with muscular bodies are perceived attractive, because they are also associated with health. http://serendip.brynmawr.edu/exchange/node/2042.

Jihan A. Kahssay said...

This was a very interesting post. I've heard about the connection between attraction and evolution. Adding the connection of endometriosis, however, flips the entire evolutionary theory on its head.

You've posed an interesting and valid question: why would evolution both reward women and punish them for being attractive? Perhaps the high occurrence of endometriosis among very fertile women is a way for evolution to correct the bias for higher births rates among girls.

If attractive women are having more children, and if they tend to birth more girls than boys, then over time, there will be a gender imbalance in the population. But, if a mutation occurs in the population that makes some attractive women infertile, then I can imagine that this misfortune serves a "corrective" function in the population by reducing fertility rates among those women who tend to give birth to more girls than boys.

This is all very interesting! Thank you for sharing!

Sam said...

“Women with these traits are preferred because they are more likely to produce offspring that will have a greater chance of survival”

First, one needs to remember that social factors play a large role here. The desire to conform to cultural norms and to gain status by having a certain type of mate most certainly play a role in what types of features certain cultures consider attractive.

Second, one needs to remember that the ultimate controlling factor is whether or not the offspring survives to reproductive maturity. Factors other than physical attractiveness contribute to this, such as intelligence, compassion, and the ability to care for children.

“So why would evolution both favor and disfavor attractive women?”

Evolution does not create optimal solutions. It simply creates solutions that are good enough to pass on genes at a survivable rate. In light of this, it is unsurprising that attractiveness is not a perfect signal for genetic health.

Pali said...

After reading this article, my brain went on a complete tangent on whether or not plastic surgery was cheating Darwin.

Ironically I found an article very quickly on the ethical implications of plastic surgery- http://jetpress.org/v20/scott.htm.

Though the issue could apply to either sex, the article is obviously impressing a woman's ethical need to disclose her surgical enhancements.

"With CPS [cosmetic plastic surgery] an illusion is created, in the sense that what one sees is not necessarily what one will get in regards to DNA. In the relationship of the individual and their mate/potential mate, there is a responsibility on the part of the individual to disclose any previous CPS."

I wonder if this ethical dilemma is a result of women being the primary recipients of plastic surgery, and how this will change as men are getting plastic surgery in greater numbers.