According to a study from the University of Louisiana Monroe, previous research found individuals living in specific regions with higher pathogen prevalence valued their mate’s physical attractiveness more than those in areas of lower pathogen prevalence. As a follow-up to this, a new study explored the theory: since people living in high-pathogen regions choose mates whose appearance is associated with stronger pathogen resistance, individuals living in high-pathogen regions would be expected to spend more time and effort on grooming to make themselves appear more pathogen-resistant.
To test this hypothesis, the average hours per day spent on grooming, i.e., showering, shaving, applying deodorant or fragrance, was obtained for both men and women from all 50 U.S. states, as well as state levels for pathogen prevalence. This information was obtained from Fincher and Thornhill, based on data from the U.S. Center for Disease Control for all states between the years 1993 and 2007. The data included diagnoses of AIDS, haemophilus influenzae, malaria, measles, meningococcal disease, pertussis, salmonellosis, shigellosis, syphilis, tuberculosis and typhoid fever. In addition, measurements per state were made in relation to health and mate suitability; i.e., life expectancy, overall physical well-being, poverty and economic disparity.
Correlations in both groups indicated that pathogen prevalence was the strongest predictor of regional differences in grooming.
The resulting model accounted for 35.7% of the variance in men’s daily grooming and 33.1% in women's. Thus, both men and women sought to improve or accentuate their own physical attractiveness in regions of higher pathogen prevalence, which was more valued by potential mates. Furthermore, the correlations in both groups indicated that pathogen prevalence was the strongest predictor of regional differences in grooming.
The authors noted possible limitations to this analysis that could be addressed in follow-up studies. The measures of grooming in this case was largely hair brushing, makeup, teeth brushing and applying deodorant and perfume, which are often more valued by men than women. Also, a follow-up study could look for regional differences in male attempts to appear taller or stronger. Another limitation to this study was its basis on U.S. states defined by historical and political borders, not necessarily by environmental criteria. Thus it is possible that different regions within the same state would have higher or lower pathogen loads.
Regardless, the current study says something about the human instinct to seek a mate who looks and smells healthier. It also nods in the direction of longer, more intensive grooming efforts. Could pathogens be a new indicator to which novel product concepts might be targeted?