If you watched our previous video on Johnny Depp, while discussing the importance of symmetry
we referenced a study which concluded “While average faces seem attractive, the most attractive
faces are not average.
Rather, there are specific deviations from the average configuration that lead to increased
perceptions of facial attractiveness in the direction of sex-typical appearances.
The basic premise of this article was that there are certain deviations from average,
which enhance the perceived attractiveness of an individual's face.
In specific the variances which improved facial attractiveness were those which were biologically
perceived to be more “male” and “female” for the respective genders.
These deviations are known as dimorphic variations.
The word Dimorphism simply means Di- two, and morphism- variance, together they mean
the two variances in human faces; that which separates a masculine face from a feminine
face.
Scientists hypothesize that dimorphic trait expression in males is dependent on steroid
hormones, such as testosterone and dihydrotestosterone.
“Since these hormones are immunosuppressive, a masculine phenotype is considered an honest
signal of immunocompetence and mate quality”.
The Immunocompetence hypothesis suggests that male facial masculinity is a handicap signal—only
the healthiest males can afford to “spend” testosterone on these ornaments while suffering
immune suppression under high testosterone loads.
The handicap signal suggests that the more costly a signal is, the more reliable the
signal is as it could not be afforded by an individual with less of that particular trait.In
this theory, since high testosterone can suppress the immune system, only genetically strong
individuals can have a dimorphic appearance as it has negative implications on the immune
system; therefore it is a reliable indicator of a strong mating partner.
Another example of this handicap theory are peacock tails, which are eye catching but
are heavy and hinder movement.
Another approach from evolutionary psychology is that women prefer a masculine face because
it is a reliable indicator of strength and fertility, and that these mating patterns
originate from hunter gatherer days.
One study in specific took 73 male photographs, and 73 female photographs.
They then manufactured a composite for both female and male faces.
The linear difference between the male and female averages represented a sexual dimorphism
dimension.
±50% of this difference was then applied to the individual faces, following which their
individual texture was mapped to the changes to retain their facial identity.
Interestingly both the masculinized and feminized faces were chosen less than the more androgenous
initial composite.
This study shows that masculinized faces are only preferred in male faces, and feminized
faces are preferred in females.
This is the uniqueness about dimorphic features.
Unlike symmetry and averageness, they are gender dependent.
One may argue what about faces such as Timothee Chalamet or any one of your tiktok pretty
boys.
While they may have more feminine features than most, they also have strong dentofacial
structure that most people take for granted.
What is a positive feature for men might be negative for females.
So while masculinization will have a negative effect on the mean population (assuming a
equal ratio of men:females), it has a positive effect on a male population.
This is why when going to a plastic surgeon it's best that their portfolio specialises
on one gender only as there are too many dimorphic subtleties to a face to get right.
This was proved in a similar study which separated male and female faces and concluded: “The
significant main effect for dimorphism showed that participants rated the masculine male/feminine
female faces as more attractive than feminine male/masculine female faces."
Since these dimorphic features develop due to high testosterone prenatally up until the
end of puberty, we would expect to see a direct correlation between testosterone levels in
males, and masculine features.
A study tested this theory and found the correlation between blood plasma levels in males, and
facial gender score.
The experiment concluded that Correlations statistical significance (p < 0.001) were
observed between free testosterone levels from cord blood and facial gender for males
(r = −0.52).
This study also tried to define dimorphism and using machine learning and found “five
linear measurements:(forehead width, nasal bridge length, nasal tip protrusion, upper
lip height and nose width) and seven geodesic (intercanthal width, forehead width, outer
canthal width, nasal bridge length, nasal tip protrusion, upper lip height and nose
width) distances as the most discriminating features between the two sexes.”
A mathematical model using these ratios was able to determine gender with 99.47% accuracy.
So to answer the question, what makes a masculine face?
The first and most obvious feature which makes someone look masculine is facial hair.
A study tested this and found that “Masculinity ratings increased linearly as facial hair
increased”.
This conclusion came after letting women rate the same face with various levels of facial
hair.
This makes sense, since facial hair is a result of the hair follicles on the jaw being stimulated
from dihydrotestosterone (DHT); a hormone synthesised from testosterone.
Women have the same facial hair follicles, but since they are less sensitive to dht,
and have less testosterone on average they don't develop facial hair.
Therefore, facial hair is not only dimorphic, it is the most obvious difference between
men and women.
However, the correlation with attractiveness and facial hair isn't as simple.
A beard disguises some of the lower third, so depending on your lower third a beard can
either improve or decrease your facial aesthetic.
A robust strong lower third is attractive, and covering up with a bread will lower your
attractiveness.
In contrast a weak underdeveloped jaw benefits by being disguised by thick facial hair.
Compare actors Tom Hardy and Henry Cavill with and without a beard, while both look
more masculine, Tom Hardy looks better with a beard, while Henry Cavill looks better clean
shaven.
Another prominent dimorphic characteristic is a pronounced brow ridge, or supraorbital
bone.
This bone is above your eye, and provides support to make your eyes look protected.
According to a article outlining the morphology and social dynamics of the supraorbital bone,
“In humans, the brow ridge is a sexually dimorphic anatomical trait…..and its growth
and development have also been related to androgen production, along with general facial
sexual dimorphism.''
Another study modeling masuline faces noted that “deeper position of the eyes in relation
to the facial plane” were dimorphic as the supraorbital protrusion makes the eyes deeper
set, which is masculine.The reason why is that a prominent supraorbital bone is an adaptation
to hunting, and intrasexual competition among men.
It’s unsurprising all 4 of these men are professional fighters.
The article goes on to conclude that “Like antlers, they are fixed and have been hypothesized
to signal dominance or aggression.''
The supraorbitalis usually projects 5-10mm beyond the eyes.
The nasofrontal angle can be used to measure the perceived protrusion of the brow ridge.
The average for males is 130 ° ± 7 °, and for females: 134 ° ± 7 °. The lower the
angle the more masculine the face appears.
In a study comparing 10 measurements of facial dimorphism, they noted that only 4 of the
10 definitions actually correlated with the sex of a face.
The average measured values are here, pause the video if you're interested.
One of these measurements was the supraorbital angle, showing the importance of a prominent
brow ridge in facial masculinity.
These 4 measurements alone had 79% success in determining the biological gender of a
skull.
Moving on, lets look at a paper published about the sexual dimorphism on the nose morphology
. This study compared the noses of 90 chilean men, and 90 chilean women to find gender specific
differences.
Nasal projection, Nasal length, and nasal base to PNR distance were all greater in males,
meaning that men had greater nose prominence and overall larger noses by size.
Conversely nasofrontal and naso-labial angles were higher in females, meaning that they
were found to have more upturned, but smaller, slender nose shapes with lower prominence
and projection.
I’ve mentioned this before, but men can get away with a lot more nose shapes, and
even your top models such as Mariano Di Vaio benefit from nasal imperfections such as a
slight dorsal hump.
Other examples are Adrian Broody and Adam Driver who are both known and celebrated for
their unique nose shapes.
Women on the other hand with these aqualine shapes tend to get them corrected as they're
such heavily masculine features as shown by these studies.
Having too straight of a nasal contour or even a concave one, can make men appear more
feminine and snub nosed if they don’t have the pretty boy features to match.
Next up, are lip variations.
While they are dimorphic for women developing under oestrogen, there was also a correlation
between 2D:4D length with upper and lower lip protrusion seen in males.
There will be an in depth video on this, but one of the craziest ideas in science to me
at least, is that you can predict the masculinity and handsomeness of a man’s face by the
ratio of his finger lengths relative to one another.
This is because the Second digit to fourth digit ratio is a measure of androgen exposure
in the womb where studies have found that relatively longer ring fingers indicate higher
testosterone.
The phenomenon can be explained since the 4th digit finger has a disproportionate high
number of androgen and estrogen receptors, so depending on the balance of testosterone
and estrogen, the 4th digit growth will be disproportionately accelerated or decreased.
In males, a low 2D:4D ratio suggests a higher ratio of testosterone:estrogen.
Surprisingly, higher testosterone:estrogen ratio (as measured in 2d:4d ratio), increases
upper and lower lip protrusion.
It’s why many men have perfectly cupid bow shaped lips but are often darker in colour
than their female counterparts.
However, since lips also develop under estrogen, the vermillion heights are equal in males
and females.
Interestingly, Hier et al. reported that females prefer fuller lips on men to a greater degree
than men do on women.
Lastly, we will be skipping over the most dimorphic part of a human face, the jaw because
there is already a full video on the topic.
For a quick summary however, men have thicker chins and more robust jaws with the jaw angle
or gonial angle being anywhere from 100-130 and for females 135-120 degrees.