Monday, October 25, 2010

Racial Differences in the Concept of Beauty

Are average composite faces the most attractive faces or are highly attractive faces markedly different from average faces? Rhee & Lee (2010) agrees with Perrett & Yoshikawa (1994) that the most attractive face is actually the average of attractive faces and that an average face; while attractive, is not the most attractive.

They also argue that previous concepts of beauty such as the divine proportion (golden ratio) are not a good measure of beauty across different races and should not be used as an overarching universal indicator of beauty. Between different races, there appears to be different characteristics that are deemed beautiful. They merged some of the most attractive female faces of African, Caucasian, Chinese and Japanese people respectively, to create the images below.

They also mentioned some of the defining characteristics of beauty for the different races.
  • African: Narrow nose, smaller and more acute eyes, smaller upper lip, slender chin compared to the average African face.
  • Caucasian: Somewhat masculine, narrow palpebral (eyelids) height, angulated and squared mandible (lower jaw), protruding cheek and fuller lips compared to the average Caucasian face.
  • Chinese: Narrow cheek, slim and thin face, lantern jaw.
  • Japanese: relatively longer face, slightly slanted eyes, sharp chin and chubby cheeks.

Unfortunately, they did not conduct any experimental study to compare attractiveness ratings of such faces versus other faces that are considered beautiful based on traditional morphometrics. It would also have been interesting to look at how the male composite faces would look like.
Rhee SC, & Lee SH (2010). Attractive Composite Faces of Different Races. Aesthetic plastic surgery PMID: 20953953
Perrett DI, May KA, & Yoshikawa S (1994). Facial shape and judgements of female attractiveness. Nature, 368 (6468), 239-42 PMID: 8145822

Thursday, October 14, 2010

The link between coffee and acute ischemic stroke onset

Do you drink coffee on a regular basis? I do. And what does drinking coffee have to do with acute ischemic stroke (caused by disruption of blood supply to part of the brain)? In a study published in Neurology, Mostofsky and colleagues investigated the relationship between drinking caffeinated coffee and the risk of acute ischemic stroke in the next hour.

Using a case-crossover design, each subject served as his/her own control. All the subjects were patients with a confirmed diagnosis of ischemic stroke. Coffee consumption information one hour before the onset of stroke symptoms was compared with their frequency of coffee consumption in the previous year.

They found that drinking coffee doubles your risk of ischemic stroke onset in the next hour compared to drinking other caffeinated drinks such as tea or cola; which may be due to lower concentrations of caffeine in those drinks.

When they looked at the frequency of caffeinated coffee intake in the previous week, they found that only people who were drinking ≤1 cup of coffee per day had increased risk for ischemic stroke in the following hour.

The take-home message?

  • Drinking coffee temporarily increases one’s risk of ischemic stroke – especially so for infrequent drinkers (≤1 cup of coffee per day).

Well, I don’t think I’m willing to forsake my coffee just yet so I’m going to have 2 cups a day instead of my usual 1 a day.
Mostofsky E, Schlaug G, Mukamal KJ, Rosamond WD, & Mittleman MA (2010). Coffee and acute ischemic stroke onset: The Stroke Onset Study. Neurology PMID: 20881275

Tuesday, October 5, 2010

What the Presence of Attractive Young Women can do to Men

Much has been said about the female preference for resources and the male preference for physical attractiveness, but at the time of James R. Roney's (2003) writing little had been done to tease out cognitive mechanisms that underlie this adaptive preference.

Roney thus set out to ascertain the ability of ecological cues to prime and activate psychological constructs related to mate attraction and establish linkages between human mating and social cognition.

In his first study, participants - young students from the 10th and 12th grades of a Midwestern high school - were made to answer three large booklets of surveys. However, the manipulation of the environment within which the surveys were answered was as follows: in the first condition, all participants were male; in the second condition, all participants were female; in the last condition, males and females were present during the study. Without knowing what the experimenter was up to, participants answered questions in the surveys, and nested in those surveys were questions related to one's attitudes towards wealth and resources.

The results fascinatingly appear to support evolutionary theories about human mating. Male students in the mixed-sex environment reported higher valuations of material wealth than did male students in the same-sex environment.

The young men in the mixed-sex condition also reported higher ratings of having an active dating life. These findings suggest that the presence of females may have primed implicit mate attraction goals and, subsequently, the activation of cognitive attitudes associated with mating objectives (detailed manipulation checks were conducted via cleverly placed questions on items such as current relationship status and mate preferences, reducing the possibility of confounding variables).

Now that the first experiment appears to be consistent with evolutionary theory predictions, Roney sought to find out if other mating goal-related attributes in men can be primed. In his second study, male participants were exposed to advertisements featuring either younger female models or older female models, after which they filled out a questionnaire.

The results again confirm evolutionary theory hypotheses - men in the younger models condition reported higher valuations of wealth (replicating the findings of the first study), had a greater desire to display/showcase talent and, interestingly, listed self-descriptive traits that increase men's odds of attracting women (this was confirmed through separate ratings of the male participants' self-descriptive traits by women), such as ambitiousness and aggressiveness.

Roney's study thus brings evolutionary psychology one step further by utilizing ecologically realistic stimuli, in the process demonstrating powerful but previously unknown psychological effects. Specific to this study, visual exposure to young women caused significant changes in the attitudes and personality trait descriptions of the young male participants. In particular, young men who were exposed to young women reported far more favourable attitudes towards material wealth than did men exposed to either other men or older women.

This makes sense because if securing a mate was an important task in ensuring the survival of one's lineage (without which those of us alive today wouldn't be here), then there should be psychological mechanisms present to facilitate the achievement of such goals, and men should thus be sensitive to cues that relate to both potential mates and resources. Using an adaptive basis for understanding psychology can also prove useful, because without this evolutionary context of mating, such stable behavioural changes demonstrated in Roney's study can, at best, only appear random and lead to invalid conclusions.
Roney, J. (2003). Effects of Visual Exposure to the Opposite Sex: Cognitive Aspects of Mate Attraction in Human Males Personality and Social Psychology Bulletin, 29 (3), 393-404 DOI: 10.1177/0146167202250221