Our brains can estimate upper body strength for fighting just from facial pictures. The idea here is that our ancestors needed to know when to fight or back off. So we have this innate ability.
(Santa Barbara, Calif.) –– For our ancestors, misjudging the physical strength of a would-be opponent might have resulted in painful –– and potentially deadly –– defeat.
Now, a study conducted by a team of scientists at the University of California, Santa Barbara has found that a mechanism exists within the human brain that enables people to determine with uncanny accuracy the fighting ability of men around them by honing in on their upper body strength. What's more, that assessment can be made even when everything but the men's faces are obscured from view. A paper highlighting the researchers' findings appears in the current issue of the Proceedings of the Royal Society.
"Assessing fighting ability was important for our ancestors, and the characteristic that the mind implicitly equates with fighting ability is upper body strength," said Aaron Sell, a postdoctoral fellow at UCSB's Center for Evolutionary Psychology and the paper's lead author. "That's the component of strength that's most relevant to premodern combat. The visual assessment of fighting ability is almost perfectly correlated with the perception of strength, and both closely track actual upper body strength. What is a bit spooky is that upper body strength can even be read on a person's face.
Maybe facial muscles get built up along with upper chest and arm muscles? Or necks become thicker? Or testosterone levels determine average muscularity as well as extent of masculine features in faces such as thick bone above the eyes.
Some major names in evolutionary psychology (Cosmides and Tooby at UCSB) were involved in this work.
Sell conducted the study with Leda Cosmides, a professor of psychology and co-director of the Center for Evolutionary Psychology; John Tooby, a professor of anthropology and also co-director of the Center for Evolutionary Psychology; Michael Gurven, an associate professor of anthropology; and graduate students Daniel Sznycer and Christopher von Rueden.
Perception of fighting ability as guessed from facial pictures correlated with measured upper body weight lifting capacity.
When the photographs depicted men whose strength had been measured precisely on weight-lifting machines, the researchers found an almost perfect correlation between perceptions of fighting ability and perceptions of strength. "When you see that kind of correlation it's telling you you're measuring the same underlying variable," said Tooby.
They also found that perceptions of strength and fighting ability reflected the target's actual strength, as measured on weight-lifting machines at the gym. In other sections of the study, the researchers showed that this result extended far beyond the gym. Both men and women accurately judge men's strength, whether those men are drawn from a general campus population, a hunter-horticulturalist group in Bolivia, or a group of herder-horticulturalists living in the Argentinian Andes.
Imagine future humans whose upper body strength and facial features become basically disconnected from each other (that can already happen with steroid usage). Innate ability to generalize from facial features won't always work. But there's not an obvious genetic fix to do for future offspring since the current rules that our brain uses will still work for some people and any genetic change in how we analyze facial features will just change which humans we make the errors about. Maybe future humans will just remove that capability in their offspring.
By Randall Parker at 2008 October 26 06:56 PM Brain Innatethat can already happen with steroid usage
If that were true, it would have affected the study. Did the study measure that effect? Or was that just conjecture on your part?
People tend to leave me be - must be the look in my face!
(or the talking to myself - that may be another red flag for them)
;-)
Seriously tho - I have noticed - both when I've been in top shape (practicing Martial Arts) - and when I've been grossly out of shape (like now) - that people do not challenge me physically - and that's generally a good thing.
Though some days I do long for a worthy opponent...
Lono: That is so good to know! I mean, that's such a problem for scrawny people in my neighborhood. A guy can just be walking around, minding his own business, and someone CHALLENGES HIM PHYSICALLY! Happens all the time. Now I can tell them it's coz their faces look wrong!
Randall: To be honest, I thought this study was farcial. The big correlation was based off of visual appearance of the upper body; the correlation upon looking at face was lower. This is common sense. We already knew that testosterone levels affect facial appearance (and even those experiments to "prove" it were pretty silly and unnecessary).
And I totally don't get the point about people evolving to make their face not match their pectorals. I mean, we have lots of plastic-surgery altered old women running around with 20 year-old faces and 60 year-old necks as it is -- it hasn't destroyed society, since people can just look at the neck to tell the truth. Unless people start evolving effeminate male faces while also inventing superclothes that can hide the bulging pectorals, I don't see how there is any value in "tricking" someone via facial appearance. I mean, someone who has bulging muscles will generally be strong -- I cannot believe someone got funding to scientifically "prove" that. The study already explained that people use the bulging pectorals to assess strength, and the correlation between face is less valuable.
Bob,
I wasn't referring to people in this study using steroids.
Joshua Allen,
I'm not saying that people misreading faces will destroy society. I'm just saying that genetically engineered appearances will be harder to read accurately.
Randell
Imaging this being automated in a video analysis program for sports betting purposes,
...and dating sites,
...and for before and after digital mug shots in Western penal systems.
An effective, objective, rating system based on automated digital photo facial profiles will be available long before any genetic engineering changes arrive in humans. That sort of digital facial recognition system will also be able to screen out plastic surgery very quickly after it is introduced.
A rapid digital "power rating" facial recognition digital video system has many implications in that one for military, police and internal security uses...but the commerical marketing uses will by far dominate the field.
You just saw one more piece of your privacy go out the window, via your facial reflection in a window.
Joshua,
Clearly I was refering to situations where agressive behavior was likely to occur - where I had would be opponents back down - without any significant input from me.
(i.e. High School, Frat Parties, Bars, Punk Rock shows, Mosh Pits, etc...)
However, if you are still unstatisfied with my response - then Bring It!!
(that's what I thought!)
It would be more useful if the researchers had controlled for body fat (which they might have done, I can't tell). Lots of Olympic weightlifters (google Hossein Rezazadeh) carry a good bit of bodyfat, because their raw strength might actually be undermined if they tried to diet and get thin.
In that case, I strongly doubt that it does already happen with steroid usage. Steroid use no doubt causes the same changes to faces that naturally acquired strength does, or it would have shown up in the study. Steroid use is fairly common especially among the men who would rate as strong.
Trent,
I expect the biggest use of imaging of faces is going to come from automated lie detection. You aware of the research on facial reading to identify statistical outlier people who are really good at watching facial expressions to detect deception? I think the US intelligence community has made use of this research. I forget but maybe someone at UCSF is the top expert in this area.
Bob Badour,
Steroids aren't going to change bone structures as much as testosterone did in utero and in youth.
Lono,
All this time I didn't know I was supposed to feel intimidated by your electronic presence.
Randall,
The flaw in your logic is the assumption that people are looking at bone structure when evaluating faces for strength. I strongly suspect bone structure has little or nothing to do with it, and the soft tissues have everything to do with what makes a strong man's face look strong. For example, when I recently watched the movie _Felon_ I kept thinking I was watching Jason Statham not Steven Dorff. I doubt Dorff's skull changed much since City of Industry or Blade.
That said, anabolic steroids do affect bone structure. Just look what growth hormone did to the Governator's face.
Randall,
Yes - well - that's the danger of anonynimity on the net - you never know if your debating a 16 year old martial arts champion or a 40 year old who lives in his parent's basement.
But I do like the fact that on the net people are willing to get up in my face, rather than avoid the confrontation - it keeps me honest anmd challenges my assumtions on a daily basis.
Well done puny one's - you provide me with hours of entertainment with your above average brains!
Bob,
An assumption that bone structure is part of the evaluation does not strike me as a flaw in my logic.
A couple of quick comments:
RE: steroid usage
Two of our samples were from college undergrads at UCSB. I doubt many used steroids, but we don't have that data. We DO however have two samples from indigeonous people including the Tsimane of Bolivia and a group in Southern Argentina. Neither group have access to artificial steroids, but our raters were just as capable of estimating their strength from the face.
RE: body weight, body fat, etc.
We controlled for both height and weight in our samples and found that people were still able to estimate strength from the body and face. In other words, if we had given them pictures of men who were the same height and weight they could still tell the strong ones from the weak ones. Also, I should mention the faces were cropped below the chin, so raters could not see the thickness of the neck in the face photographs.
A couple of quick comments:
RE: steroid usage
Two of our samples were from college undergrads at UCSB. I doubt many used steroids, but we don't have that data. We DO however have two samples from indigeonous people including the Tsimane of Bolivia and a group in Southern Argentina. Neither group have access to artificial steroids, but our raters were just as capable of estimating their strength from the face.
RE: body weight, body fat, etc.
We controlled for both height and weight in our samples and found that people were still able to estimate strength from the body and face. In other words, if we had given them pictures of men who were the same height and weight they could still tell the strong ones from the weak ones. Also, I should mention the faces were cropped below the chin, so raters could not see the thickness of the neck in the face photographs.