You may find it stressful to contemplate this study about attractiveness:
“Facial attractiveness is related to women’s cortisol and body fat, but not with immune responsiveness,” Markus J. Rantala [pictured here, below], Vinet Coetzee, Fhionna R. Moore, Ilona Skrinda, Sanita Kecko, Tatjana Krama, Inese Kivleniece and Indrikis Krams, Biology Letters, epub May 22, 2013. The authors, variously at the University of Turku, Finland, the University of Pretoria, South Africa, the University of Dundee, Scotland, the University of Daugavpils, Latvia, and the University of Tartu, Estonia, explain:
“we photographed young Latvian women, vaccinated them against hepatitis B and measured the amount of specific antibodies produced, cortisol levels and percentage body fat. Latvian men rated the attractiveness of the women’s faces. Interestingly, in women, immune responsiveness (amount of antibodies produced) did not predict facial attractiveness. Instead, plasma cortisol level was negatively associated with attractiveness, indicating that stressed women look less attractive.”
Here is a photograph of lead author Markus Rantala on horseback:
(Thanks to investigator Erwin Kompanje for bringing this to our attention.)