November 02, 2005
Women With Higher Estrogen Seen As More Attractive

Sex appeal comes from a hormone. More estrogen makes a woman's face prettier.

Women with high levels of the sex hormone oestrogen have prettier faces, research suggests.

The findings make evolutionary sense - men are attracted to the most fertile women, the University of St Andrews team told a Royal Society journal.

Measurement of estrogen levels combined with attractiveness ratings showed a relationship.

Miriam Law Smith and colleagues photographed 59 women, aged between 18 and 25, every week for six weeks. On each occasion, they provided a urine sample for hormone analysis and gave information on where they were in their menstrual cycle. None of the women wore make-up, nor were they taking the contraceptive pill.

The researchers then selected the photograph of each woman that had been taken at the time of her highest urine-oestrogen level. As expected, this correlated to the point of ovulation in the women’s menstrual cycles. These photographs were rated by 14 men and 15 women, also aged 18 to 25, for attractiveness, health and femininity.

Make-up hides the effect.

Women with higher levels of oestrogen were rated as more attractive, healthy and feminine looking. Interestingly, no relationship between appearance and oestrogen was found in women wearing make-up. The researchers believe that while make-up improves facial appearance it may be masking cues normally seen in the face.

That men should be attracted to more fertile women makes sense from an evolutionary perspective. Also, the relationship between hormone levels, shapely bodies, and fertility is well-established. Women with higher levels of estradiol are about 3 times more likely to get pregnant. See my post "Women With Hourglass Bodies Have More Reproductive Hormones".

Eventually stem cell therapy and gene therapy will be widely used by women to enhance their feminine appearance. The average level of attractiveness of both men and women will be far higher in the future. Once Strategies for Engineered Negligible Senescence (SENS) become available everyone will look young and highly attractive.

Share |      Randall Parker, 2005 November 02 11:45 AM  Brain Sexuality

James Klee said at November 2, 2005 1:49 PM:

In the past century the maximum human lifespan increased by -- what -- six months?

And now eternal youth / SENS / nanotech replicators for all of us are just a few years out. . . RIGHT

Somehow I liked the existentialist JP Sartre axis a lot better than the triumphalist scharaffenland fantasies of today reality-denying milquetoast materialist set.

Carpe fucking Diem, "be what you come here for" because tomorrow will be too late.

Brett Bellmore said at November 2, 2005 3:48 PM:

And for how much of that past century did we have the human genetic code on display before us? For how much of that past century did we understand the mechanics of how a cell functions? For how much of that past century did we even have a clue as to the basic mechanisms of aging?

You can't solve a problem until you understand it, and have the tools. Now we understand it, and we're getting the tools. That's a HUGE difference.

Randall Parker said at November 2, 2005 5:34 PM:

James Klee,

I picture you right before the Kitty Hawk flight saying "For centuries humans could never fly. And you are telling me in a few years people will fly.... RIGHT".

Or, hey, how about desktop computers? "Everyone knows that computers take up whole rooms".

I remember when I started college no one could sequence DNA. Then while a freshman the Sanger and Gilbert methods were published. A few years later a group at CalTech took a mass spectrometer developed for the Mariner mission and built the first automated sequencing device. DNA sequencing costs have fallen by many orders of magnitude since then. Earlier this year a single paper from a Harvard group showed how to drop costs another order of magnitude.

Biotech is following the pattern of electronic computers with shrinking parts, faster assays, and orders of magnitude drops in costs. Microfluidics will speed up the rate of progress by orders of magnitude in the next couple of decades. Then SENS will be within grasp.

James Klee said at November 2, 2005 6:11 PM:

I return to my initial statement: zero progress in the maximum lifespan. Despite a century of incredible gains in medical technology and everything else.

How many endotherms are there with our metabolic rate and a substantially greater lifespan than Homo Sapiens?

And Bellmore is claiming that we understand the "mechanism" of how a cell functions. OK. What determines protein folding conformation? How does enzyme transport in the cell occur? Where does consciousness come from?

DNA sequencing is nice, but it would be much more useful to understand the principles of self-organization. We are, to paraphrase Rumsfeld, in the place where (most of us) don't even know what we don't know. And from that place of ignorance, amazing breakthroughs always seem "just around the corner". For example, strong AI which is always 5-10 years out for the past 5 decades!

It's a long, long way from reality to some kind of Kurzweilian fantasy of "downloads", superhuman AI, replicating nanobots, and SENS immortality.

Randall Parker said at November 2, 2005 6:38 PM:

We had zero progress in curing many diseases until suddenly we could cure them. We had zero progress in flying until suddenly we could fly. We had zero progress making rockets. Progress was made. People walked on the moon.

Your endotherm comment: That is pertinent how exactly? How many endotherms have our level of intelligence? We are going to make the breakthroughs using our brains and our computers and other tools. The accomplishments of other species are far less because they are much less intelligent.

Understand the principles of self-organization? We do not need big theoretical breakthroughs. We just need the ability to grow replacement parts and fix existing parts.

We do not need superhuman AIs or replicating nanobots to grow replacement parts. AI is a much much harder problem than organ replacement or stem cell therapies.

James Klee said at November 2, 2005 6:52 PM:

Growing cloned organs is probably quite feasible. Most of them can probably be transplanted successfully. Some, like skin -- maybe not.

How do you replace the brain? Obviously you don't. So you live to be 90-120 until the brain becomes hopelessly worn out.

How do you fix the brain? Now we are back to Kurzweilian nanotech.

Modern science can probably let most of us live to be 90-120 years old. A great accomplishment. But immortality it ain't.

Randall Parker said at November 2, 2005 7:58 PM:


I've repeatedly stated that the brain is the hardest part of rejuvenation.

If the rest of the body can get rejuvenated then at the very least that will reduce the oxidative stress and toxins from the rest of the body and improve brain nutrition as well.

But what will become possible for treating the aged brain?

1) Use antibodies to remove extracellular junk and probably some intracellular junk as well. This has already been done in a clinical trial against amyloid plaque that is involved in Alzheimer's. One problem is that trial was that a very small fraction of the patients got brain inflammation. This problem will be solved either with monoclonal antibodies or better vaccine designs.

2) Send in stem cells to replenish depleted neural stem cell reservoirs. Eventually genetically engineer those replacement stem cells to last longer and to create a better biochemical environment for existing neurons.

3) Send in gene therapies to fix damaged genomes in old neurons and in old glial cells.

Brett Bellmore said at November 3, 2005 4:13 AM:

I don't believe in "immortality" either; Even if you completely abolished aging, accidents would keep the average lifespan down around a couple hundred years. But slow aging even a bit, and you completely change the dynamics of the population, drastically reducing end of life fragility. A society where healthy people are dying in skiing accidents in their 80's is vastly different from one where they're dying of vascular accidents while bed ridden.

Bulldog said at November 3, 2005 4:43 AM:

I like discussing women with hourglass figures and lots of estrogen effect. Imagine a world where all women are beautiful and stay beautiful in their prime for hundreds of years. That's a world where feminine beauty is taken for granted, but hey! RP makes a good point that every problem stays unsolved until it's solved.

Mthson said at November 3, 2005 5:12 AM:

If the rate of accidental death or homicide was 1 in 1000 and the average life expectancy was 80 years, that would assumedly predict, if all else was equal, that the average life expectancy sans disease would be 80,000 years before experiencing accidental death or homicide. If that's an adequate prediction, the speculative discussion should probably deal with other concerns.

michael vassar said at November 3, 2005 7:08 AM:

Brett: With MNT we should be able to keep accidental deaths way down. What does it take to kill someone with a well designed vasculoid, broadcasting biomonitors, and nanomedicine for repair? Massive heat would do it, or vibration or acceleration intense enough to scramble a saphire supported brain, or many many megarads of radiation. Or depression of course, if you weren't willing to treat it. Accidents as we know them are a non issue.

Randall: You mention monoclonal antibodies for cleaning up amyloid plaques. I have been waiting for well over a decade for them to have a major medical impact. Why the delays?
Any other important causes of brain deterioration?

Brett Bellmore said at November 3, 2005 9:16 AM:

Accidents would be a non-issue if it weren't for risk homeostasis. ;)

Bob Badour said at November 3, 2005 12:52 PM:


I would not get too hung up on any one technology. I have been waiting for "bubble memory" to have a measurable impact since the early 1980's. Does it really matter whether it ever did? By 1982 standards, dynamic ram is now free.

Does it really matter whether the ram uses 'bubble memory' or cmos or nmos or jfet? Not at all. Does it matter whether people researched 'bubble memory' back in the early 1980's? Yes, absolutely. Who knows what specific technology will provide the next breakthrough until we try a bunch of technologies? And for all I know, those investigations led to a key discovery for some other technology.

Will it really matter in 20 years whether monoclonal antibodies solved any particular problem? No. It is just as likely we will find something even better in the interim.

Randall was pointing out promising interventions we will investigate that a few years ago we didn't even know to consider.

Jessica said at November 3, 2005 4:03 PM:

Yea I think in 20 years it wont matter what problems they solve.

divus said at November 3, 2005 4:10 PM:

"How many endotherms are there with our metabolic rate and a substantially greater lifespan than Homo Sapiens?"

Maybe one... From what I've read it seems bowhead whales have core temps. slightly higher than ours, and recent data hints at max lifespans in excess of 150yrs despite having orders of magnitude more cells(which should significantly increase cancer risk). Not sure about their metabolic rate.

"Growing cloned organs is probably quite feasible. Most of them can probably be transplanted successfully. Some, like skin -- maybe not.

How do you replace the brain? Obviously you don't. So you live to be 90-120 until the brain becomes hopelessly worn out."

Many centenarians manage to preserve most cognitive function, and that is with a deterioration of all the life support organs. I'm pretty sure the brain can most likely last substantially longer given a rejuvenated life support system and glial cell rejuvenating therapies. Not to mention gene therapies to clean up protein aggregate diseases, and spur up renewal in the appropriate places.

Brett Bellmore said at November 3, 2005 4:39 PM:

"Not sure about their metabolic rate."

A cold watery enviroment helps, but still, given square/cube considerations, I'd guess it's lower than human, as evidenced by the fact that they don't cook themselves.

The total metabolic activity per unit mass over a lifetime is relatively constant, and if we're going to beat that limit, it's going to take some modification of the mitochodria, as has been suggested in SENS. Especially in the brain, where cell replacement, while it does take place to *some* extent, is very limited.

AA2 said at November 3, 2005 4:53 PM:

Bulldog - I like the idea of everyone being very fertile and youthful as well. One of the reasons longevity doesn't have the greatest image at the moment is extending life from 5 years for women say from 80 to 85.. gives them extra years when they are in their 80's. Not something to get overly excited about. Although of course those people see a slower aging process so got more life at each stage.

However imagine a world where you can be youthful for a very long time, and more attractive. It would totally change our civilization and for the better.

AA2 said at November 3, 2005 5:09 PM:

Mthson - That seems like a decent prediction. Right now if the accident rate stayed the same men would live to 1500 and women to 5000 I believe on average... if they weren't dying of 'natural' causes like disease and aging. As Randall has said if people had thousands of years on the line they would likely be far more careful regarding the big killers like automobile accidents.

Which we already see a decline every year in America in the number of fatalaties on the road, since the 70's.

Doug said at November 3, 2005 5:56 PM:

Speaking of risk, don't we have to contend with the problem that Leon Kass and those of like views are trying to make sure technologies that extend lifespan aren't implemented? If I'm correctly informed, Kass thinks most of us aren't worth keeping around for more than about 45 years, not our current 75 or so, let along 1,000 or 5,000 years. Are views such as his getting any foothold, I wonder?

Doug said at November 3, 2005 6:50 PM:

While we're all waiting for nanobots to come along, march through our bodies, and pack off all the rho-null mitochondria and gunked-up lysosomes, is anyone aware of any accumulating evidence as to how people who have been on supplement regimen's such as LEF's for the last decade or so have been doing? If LEF's supplementation recommendations have very much value, we should soon be able to discern a cleaving of the American population into two broad, statistically distinguishable populations as regards health, appearance, and longevity.

And I'm beginning to find that the notion that one can add at least a few years of youth and health to one's life fairly well-supported, at least by my own sample of 1--about the shortcomings of which sample size I'm quite aware. Having spent a few years taking DHEA, co-enzyme Q10, and anti-oxidants, having dipped into hGH and testosterone replacement for a while, having generally kept up moderate exercise and "kept the weight off," and having lately learned the importance of elevating my vitamin D concentration, getting plenty of EFAs, and keeping my blood glucose low, I seem to have kept about 10 of my 42 actual years from showing up in my face and body. I'm starting to wonder if it will prove feasible to have the appearance, energy, and health of a fit 30-something at age 50, and then just maybe at age 60. It seems reasonable to me that much of the damage incurred by our bodies, once it's incurred, is irreversible with our present technology. Nevertheless, it seems that even with my uneven level of scrupulosity about health matters, it's possible to go through one's adult years aging at only about half the usual rate.

Randall Parker said at November 3, 2005 7:05 PM:

A few points about the brain:

1) The brain is 2% of body mass but consumes 20% of metabolic energy.

2) It is surprising the brain does not wear out more rapidly given the amount of energy it consumes.

3) The brain's food supply and biochemical environment certainly deterioriate as the rest of the body ages and the quality of the blood going into the brain deterioriates. Rejuvenate the rest of the body and the brain will function much better. Prevent the rest of the body from aging in the first place and the rate of aging of the brain will decelerate due to less oxidative stress.

4) Glial cells support neurons with nutrients. Send in stem cells for glial cells and the nutritional status of many neurons could be improved and therefore function would be improved.

5) Removal of accumulated junk would reduce the oxidative stress load of neurons and also free up neuronal volume for needed metabolic activity. So junk removal provides a double whammy benefit.

6) Gene therapies are essential for brain rejuvenation.

Michael Vassar,

Monoclonal antibodies and Alzheimers: You got me. It is my vague memory that this avenue is actively being pursued though.

Randall Parker said at November 3, 2005 7:11 PM:


I do not see people like Leon Kass as having much impact on slowly the rate of increase in biotechnologies. The biggest obstacle we face in trying to get SENS is the reluctance of practicing biologists to state that SENS is a goal worth striving for.

But I see a big shift in attitudes. About 8 years ago me and a handful of other people were discussing rejuvenation with Aubrey de Grey in the Usenet group. Now major media publications run stories on his arguments and a growing number of scientists come to his SENS conferences. SENS is steadily becoming a less and less marginal idea. It is gaining acceptance. More people write about it and talk about it.

When some big stem cell therapy successes are achieved people are going to start asking why not fix everything? If you can fix and replace parts then why can't SENS be achieved?

Randall Parker said at November 3, 2005 8:17 PM:


I'd be a lot more impressed with supplement regimes if supplement regimes could cause other animal species to live longer in lab settings. But supplements help very little in other animals. I doubt they help extend life much in humans either.

Your best bet is to avoid toxins and eat higher quality food. Though I think vitamin D is a good thing to take.

Michael Clayton said at November 4, 2005 1:48 AM:

James wrote;

In the past century the maximum human lifespan increased by -- what -- six months?

And now eternal youth / SENS / nanotech replicators for all of us are just a few years out. . . RIGHT

Somehow I liked the existentialist JP Sartre axis a lot better than the triumphalist scharaffenland fantasies of today reality-denying milquetoast materialist set.

Carpe fucking Diem, "be what you come here for" because tomorrow will be too late

Yes there are a lot of optimists out there regarding the time to achieve longer lives. Is your objection just the time frame or more one of principle?
Some things that look easy turn out to be hard, while the reverse is also the case, the last century is full of examples. We are 'biological machines' after all, so it's a matter of a short time (15+ years) before significant advances start to be made, ... from what I've read :)

Michael Clayton

divus said at November 4, 2005 4:05 AM:

“A cold watery enviroment helps, but still, given square/cube considerations, I'd guess it's lower than human, as evidenced by the fact that they don't cook themselves.”

Question is how much lower, that water dissipates heat much much better than air, tens of times better(IIRC), yet despite that whales maintain body temps that I've heard are close to other large animals, pressumably land based ones.

On top of that, the increased number of cells, ensure many more defects abound in the organism and greater probability of cancer, which together with exposure to natural/artificial bio-accumulative toxins, and overall exposure to non-accumulative toxins through such a potentially long lifespan should help the accumulation of dmg gap get closer.

“The total metabolic activity per unit mass over a lifetime is relatively constant, and if we're going to beat that limit, it's going to take some modification of the mitochodria, as has been suggested in SENS. Especially in the brain, where cell replacement, while it does take place to *some* extent, is very limited. "

There are exceptions to that. I've heard that within some species higher metabolic rate correlates with higher lifespans. Also comparisons between some species with high metabolic rates shows substantial lifespan differences that can be exponentially greater, If I'm not mistaken...

James Klee said at November 4, 2005 7:09 AM:

We are 'biological machines' after all,

That's certainly the most popular hypothesis among scientists today, anyway.

Carl Shulman said at November 4, 2005 5:22 PM:

Accidents would NOT limit life expectancy to a few hundred years.

15-24 year olds current have an annual mortality rate of 81 per 100,000.

This CDC resource gives the breakdown of different types of death by injury, including suicide, homicide, and accidents.

Only 55.7 out of the 81 deaths above are caused by injury: the rest are due to the biological factors that would be eliminated by the same biotechnology leading SENS. When we exclude homicide and suicide the numbers are even smaller.

For white, non-Hispanic females age 15-24 unintentional mortality was 23.31/100,000. 19.45 of those were transportation accidents, which should be essentially eliminated by self-driving cars and the like. I could trim off another couple of points with improvements in fire prevention/control, lifeguarding, etc. So we get to a mortality rate of ~2/100,000. At that mortality rate half of a cohort would still be alive after 35 millenia.

That should be more than enough time to work out the kinks in uploading...

Brock said at November 5, 2005 8:51 AM:


I wouldn't be so sure about that. People don't drive their cars too fast because they really need to get to the grocery store in 5 minutes instead of 7; they just like the thrill. Make cars self-driving and they'll find someone other way to off themselves. IMO, the only way to get deaths down to ~2/100,000 is to get their appetite for risk down, either by pharmaceuticals or some other method.

On the topic of "Can't do it 'till it happens", I would say that I agree with Randall far more than James Klee. James does not understand Kurzweil's argument about accelerating returns. Of course we haven't extended the max lifespan in the last century more than 6 months. If the 21st century were a linear extrapolation from the 20th, then we'd get another 6 months; but the relationship isn't linear.

Also, there's two mechanisms at work, steady (accelerating) progress, and radical breakthroughs. Moore's Law is an example of the former; this could be an example of the latter:,,1627657,00.html

No one can predict the latter, but they seem to happen often enough that we can have faith in their happening again.

Carl Shulman said at November 6, 2005 7:15 AM:


I don't think that risk homeostasis operates in quite the way you describe, across activities. Improved contraception, legal abortion, and HIV medication lead people to undertake more risky sexual practices, not to go bungee jumping. Seatbelts and airbags lead to more reckless driving, and not consuming massive amounts of unidentified drugs at parties. If you eliminate a whole class of risk, e.g. self-driving cars (which would likely be legally mandated, as an ordinary driver would be at least as risky relative to automated cars as a drunk driver is to sober one)you won't increase risk tolerance in other areas to 'keep the average up.'

Randall Parker said at November 6, 2005 8:47 AM:

So far the discussion about risk and accidents has left off an important factor: Selection effects.

The people who die of accidents in a 100 year life span are, on average, more accident prone and more risk taking those who survive. Over a period of thousands of years (making the simplifying assumption of no cognitive reengineering) the more risk prone would die and the background accident rate would drop.

Now, lots will change in thousands of years. People might become cyborgs that can better withstand and avoid accidents. Nanobots might take over. But my point is that we are not all equally accident prone.

Psychometrics researcher Linda Gottfredson has pointed out that IQ is predictive for premature death and car accidents:

6. A large followup of Australian veterans found that IQ was the best predictor of death by age 40 (had 50+ predictors). Vehicle fatalities were the biggest cause (as is typical), and, compared to men with IQs of 100+, men of IQ85-100 had twice the rate and men IQ 80-85 had three times the rate. (Remember, SES could not explain this.) The US (and apparently Australia) forbid induction of persons below IQ 80 because they are not sufficiently trainable--found out the hard way.

Dumber people wll die off at faster rates. So accident rates will drop as they die and smarter people remain alive. Biotechnology that raises IQ will lower accident rates substantially.

divus said at November 6, 2005 9:05 AM:

With regards to risk-taking behavior, we've also to keep in mind the advent of fully immersive vr-sims.

AA2 said at November 6, 2005 5:56 PM:

Doug your supplement/steroid regime seems to be a good idea to me. Growth hormone isn't liked by life extensionists that I read online, but I like the looks of it when I get older. I think it has to be a big factor in the decline in the activity of stem cells for example the hormonal signals. Young people don't just have healthier cells, they regenerate faster as well.

It is a very good sign that you are already seeing a divergence between what age you look and what your chronological age is.

Erik Holland said at November 30, 2005 1:02 AM:

For those who are interested, I have provided additional data on this study here, including the photographic comparison of the composite faces based on outlier estradiol values. I have also cited related data -- including the data from Jasienska et al.(2004) -- here and provided some anthropological data here concerning the subtlety of masculinity-femininity, which can be used to describe with some precision how feminine or masculine different women are.

Shay said at November 21, 2011 2:18 AM:

I don't necessarily feel like I am educated enough to hold an argument on this matter, but I do have one underlying concern. If diseases, viruses, harmful bacteria and fungi are mutating at a fairly quick rate I can't help but wonder what makes you think that they cannot mutate past your scientific advances. We already have over growth of cells (cancer) and viruses that can mimic our own cells natural frame work (HIV & AIDS) that we have not been able to cure. I have no doubt in my mind that by the time these scientific advances are put into affect that we will have a cure for both cancer and HIV, leaving me without concern about the previously mentioned overgrowth of cells due to more cells being introduced to the body, but lets take into consideration if we get a mutated form of HIV that wipes out cells faster than we can replenish them with stem cells then we will still face death at a considerably slower rate but no where near the range of 1000 to 5000 years. Also, if we come across a mutated virus, bacteria, ect with a high exposure rate; who is to say we don't just go right back down to the same approximated life span?

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