Human's Cognitive Ability to Assess Facial Cues from Photographs: A Study of Sexual Selection in the Bolivian Amazon

June 9th, 2010
Background: Evolutionary theory suggests that natural selection favors the evolution of cognitive abilities which allow humans to use facial cues to assess traits of others. The use of facial and somatic cues by humans has been studied mainly in western industrialized countries, leaving unanswered whether results are valid across cultures.

Methodology/Principal Findings: Our objectives were to test (i) if previous finding about raters' ability to get accurate information about an individual by looking at his facial photograph held in low-income non western rural societies and (ii) whether women and men differ in this ability. To answer the questions we did a study during July-August 2007 among the Tsimane', a native Amazonian society of foragers-farmers in Bolivia. We asked 40 females and 40 males 16󈞅 years of age to rate four traits in 93 facial photographs of other Tsimane' males. The four traits were based on sexual selection theory, and included health, dominance, knowledge, and sociability. The rating scale for each trait ranged from one (least) to four (most). The average rating for each trait was calculated for each individual in the photograph and regressed against objective measures of the trait from the person in the photograph. We found that (i) female Tsimane' raters were able to assess facial cues related to health, dominance, and knowledge and (ii) male Tsimane' raters were able to assess facial cues related to dominance, knowledge, and sociability.

Conclusions/Significance: Our results support the existence of a human ability to identify objective traits from facial cues, as suggested by evolutionary theory.

More information:
Undurraga EA, Eisenberg DTA, Magvanjav O, Wang R, Leonard WR, et al. (2010) Human's Cognitive Ability to Assess Facial Cues from Photographs: A Study of Sexual Selection in the Bolivian Amazon. PLoS ONE 5(6): e11027. doi:10.1371/journal.pone.0011027

Provided by Public Library of Science

This Phys.org Science News Wire page contains a press release issued by an organization mentioned above and is provided to you “as is” with little or no review from Phys.Org staff.

More news stories

Expectations high for next Xbox

It's almost time for a new Xbox. Eight years have passed since Microsoft unveiled the Xbox 360, double the amount of time between the original Xbox debut in 2001 and its high-definition successor's launch ...

NEC phone is liquid-cooled and gender-specific

(Phys.org) —Pink is the color of princess fairy-tale gowns, magic slippers, upscale cupcake icing, and everything else favorable to girls who just want to be girls. "Ladyphones" appear to be concepts for ...

Finnish start-up launches smartphone to rival giants

A group of ex-Nokia employees who quit over the company's decision to abandon the planned MeeGo operating system in favour of Windows presented their own smartphone on Monday, hoping to rival the sector's ...

Congress gets mixed advice on regulating drones

(AP)—The growing use of unmanned surveillance "eyes in the sky" aircraft raises a thicket of privacy concerns, but the U.S. Congress is getting mixed advice on what, if anything, to do about it.

New immune system discovered

(Medical Xpress)—A research team, led by Jeremy Barr, a biology post-doctoral fellow, unveils a new immune system that protects humans and animals from infection.

Lab sets a new record for creating heralded photons

(Phys.org) —Entanglement, by general consensus of physicists, is the weirdest part of quantum science. To say that two particles, A and B, are entangled means that they are actually two parts of an inseparable ...