dating

Physical Attractiveness

Male Body Attractiveness

The most important physical attribute related to how women perceive male attractiveness is the waist-to-chest ratio (WCR). This explains ~50% of the variance of attractiveness Swami and lower is better down to at least 0.7 Singh Swami. Likewise, broad shoulders are attractive Horvath, and it's not quite clear what combination of waist/hips and chest/shoulders are driving the correlation.

After that come BMI, with an optimal BMI of around 22 Characteristics of male attractiveness for women Swami and explaining ~20% of variance, though significantly less (~4%) after the WCR is accounted for Visual perception of male body attractiveness.

Finally, we have the waist-to-hip ratio (WHR) which explains less variance and has an optimal value estimated between 0.8 and 1.0 - quite a lot of uncertainty here Singh Characteristics of male attractiveness for women Visual perception of male body attractiveness Hames.

Given all the above, its unsurprising that waist fat negatively correlates with attractiveness Horvath, since it raises BMI and lowers WCR.

The relationship between height and attractiveness is somewhat puzzling:

Females expressed a general preference for dating males taller than themselves and reported dating taller males more frequently but did not rate their tall male dates as more attractive. Moreover, no relationship was found between the height of the male subjects and their self-reported dating frequency. Interestingly, females did rate a photographed male as more attractive when he was depicted as tall than when he was depicted as short relative to an adjacent female.

Another study found height accounted for ~5% of attractiveness but that it matters significantly more for tall women and less for short women.

Flaccid penis size increases attractiveness up to ~4 inches but had limited effect beyond that. This accounted for ~6% of attractiveness Mautz.

Converting the variance explained (r^2) into correlation coefficients (r), we can vaguely think of male attractiveness as being

0.7 * WCT + 0.22 * ( height + flaccid_penis_size - BMI ) + 0.60 * other_factors

todo: muscle mass Brierley Durkee

Distribution of Traits

Official shoulder data is lacking Watson, with the latest dating back the early 1960s Stoudt. For men, they found an average circumference of 39.2" (SD=3.2"), thought it varied with age:

The average waist girth was 35.0, and it showed a different age-related trend:

The suggested average WCR is 0.89 :

The average shoulder-to-hip ratio (SHR) is claimed to be 1.18 Hames. Between 1988 and 1994, the average adult male shoulder width was 16.1 inches Watson. The average chest circumference in the early 1920s was ~33.6" (SD=2") for men, while the average height was rouoghly 5' 7.5" Wissler. See also Veale for the distribution of penile size.

Female Body Attractiveness

The optimal BMI is ~20 and accounts for 74% of female attractiveness . This is significantly more than the WHR, which accounts for a mere 2% Reinhardt Female and male perceptions of female physical attractiveness in front‐view and profile Wang Visual cues to female physical attractiveness Kościński. However, the relationship between BMI and attractiveness varies quite a bit between cultures Hames Conley.

While women think smaller breasts are more attractive, men don't really care Horvath.

Shorter females were preferred more as dates, were dated more frequently, and were rated as more attractive than taller females regardless of the height of the male subjects.

Symmetry is also preferred Is symmetry a visual cue to attractiveness in the human female body?.

Age

Age predicts attractiveness but is less significant than BMI (at least in Asian women) Much more than a ratio: multivariate selection on female bodies. One fascinating result is that people are terrible at estimating a woman's age Wang but that their guesses of age are strongly correlated with BMI. This suggests that age actually has minimal impact on how attractive a woman is perceived if you've controlled for BMI.

While I can't find find a single study that actually reports the coefficients from a model including both age and BMI, Wang do provide their data. A simple linear multivariable model shows that BMI is far more important. Unfortunately, their sample consists of only 20 silhouette photographs, but the general finding is that BMI is far more predictive. In the UK, a one point increase in BMI is associated with a 0.37 point decrease in attractiveness (0.06), while a ten year increase in age is associated with a 0.07 (0.23) point decrease in attractiveness. Results are generally similar among the other 8 countries examined, with a 1 point increase in BMI having a larger effect than a decade of age in all 9 countries.

I also found Żelaźniewicz, which provides raw data relating BMI, age, and womens' facial attractiveness in their supplemental information. They find a one point increase in BMI is associated with a 0.09 (0.02) point decrease in facial attractiveness, while a ten year increase in age is associated with a 0.13 (0.03) decrease in facial attractiveness.

In both datasets, age's slope is cut by more than 3x once BMI is accounted for.

The evidence is kind of thin given that the only two studies I could find used full-body silhouettes and face images. However, note that from age ~21 to age ~37, the average person's BMI increases by ~3.5 points. This combined with the above studies suggest that most of the "penalty" women experience as they age into their late 30s comes from gaining weight rather than simple aging - at least with regards to physical

Facial Attractiveness

Male facial attractiveness is largely characterized by symmetry, prominent cheek bones, broader chins, and a large brow ridge.

Averaging faces together using software results in faces that are viewed as more attractive Averageness. Some people believe this is because the resulting face is more symmetrical, while others believe that we subconsciously average the faces we see into a "prototype", which makes it attractive. There is some evidence for the latter theory:

This principle transcends culture. For instance, Coren Apicella and her co-workers from Harvard University[22] created average faces of an isolated hunter-gatherer tribe of 1,000 in Tanzania, Africa, the Hadza people. Hadza people rated the averaged Hadza faces as more attractive than the actual faces in the tribe. While Europeans also rated average Hadza faces as attractive, the Hadza people expressed no preference for average European faces. Apicella[22] attributes this difference to the wider visual experiences of the Europeans, as they had been exposed to both Western and African faces. Thus the indifference of the Hadza towards average European faces could have been the result of lacking the European norm in their visual experience.[23] These results suggest that the rules for extracting attractive faces are culture-independent and innate, but the results of applying the rules depend on the environment and cultural experience.[19][24]

but it is also probably not complete:

Despite these findings, David Perrett and his colleagues[24] found that both men and women considered that a face averaged from a set of attractive faces was more appealing than one averaged from a wide range of women's faces, aged 20–30 years. When the differences between the first face and the second face were slightly exaggerated the new "exaggerated" (or "caricaturized") face was judged, on average, to be more attractive still. Although the three faces look very similar, the so-called "exaggerated face" looks younger: a slimmer (less wide) face, and larger eyes, than the average face. It also had a narrower lower jaw and smaller nose-to-mouth, and nose-to-chin distances than the average face. Since the same results were obtained using Japanese subjects and viewers, these findings are probably culture-independent, indicating that people generally find youthful average faces[30] sexually the most attractive.[24]

Because it's 2020, someone has trained a ML model to predict facial attractiveness SCUT-FBP5500: a diverse benchmark, and they've provided the data to replicate their results Github, meaning we'd no longer have to wonder how attractive we are if someone would just make a website that ran the model. The main downside is that these images are not a random sample of the population - they include, for instance, celebrities.

Among pairs of identical twins, the more symmetrical is almost always the more attractive and the attractiveness differential grows proportionally with the symmetry differential Mealey. Indeed, given the existence of measurement error, it seems plausible to me that after controlling for genetics, symmetry is pretty much all that's left for determining facial attractiveness.

Heterogeneity

All of the above examines how certain factors predict the average rating you'll get from people of the opposite sex. However, there is significant heterogeneity in these ratings. Using Debruine's dataset How many raters do I need?Face Research Lab London Set I computed that the average rater's ratings correlates with the average rating with $r \approx 0.6$. That's for facial attractiveness.

In other words, two raters' ratings will correlate with $r^2 \approx 0.36$. For instance, suppose we rescale ratings to have mean 1 and standard deviation 1 and suppose your rating is 0 (average). 5.5% of the opposite sex will still rate you as being in the top 10% of attractiveness. In other words, there is significant disagreement among people regarding how attractive a face is.

Unfortunately, I haven't been able to find similar data for full-body attractiveness, but there is significantly more heterogeneity in ratings after speed dating.

Rando On The Internet

The internet author hotelconcierge claims to be a doctor (and maybe psychiatrist, I can't remember). He has an interesting theory regarding physical attractiveness hotelconcierge (start at "artificially-induced symmetry").

He extrapolates from studies of facial prototyping to the whole body. He notes that across cultures men typically prefer smaller waist-hip-ratios than the average young woman, there is a large positive association between the average ratio of young woman and the ratio preferred by men.

He than expands this further, postulating that this explains much of non-physical attraction too, where we form prototypes of what romance looks like and who we're attracted to:

Our prototypes are constructed from the narratives we observe. Perhaps in Babylon these narratives were learned through real world experience, but this is the 21st century, schizoid man. Lived romance accounts for 0.1% of our exposure to boy meets girl. The rest comes from pixels.

[ Disclaimer: I generally have a hard time knowing how seriously to take hotelconcierge and the very similar The Last Psychiatrist The Last Psychiatrist. Sometimes I think they're insightful, other times barely coherent. ]

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