Why are close-set eyebrows better than wide-set eyebrows?

A study in Journal of Comparative Human Biology observes that “In pubertal males, a high testosterone-to-oestrogen ratio causes an overall elongation of the face, relatively smaller eyes, a larger nose, the lateral growth of the cheekbones, mandible and chin, the forward growth of the superciliary arches and glabella region and the lengthening of the lower face, giving the face a more robust shape”. A shorter glabella is preferable for men because it gives an impression of robustness, explained by the higher testosterone ratio. The study further finds that the glaballar area is sexually diamorphic “Differences of 15–24% in size occurred in the area of the eyebrow ridges, the lateral margins of the forehead, the nostril wings, the masseter muscle region and, surprisingly, in the glabellar area”.

In a twist from common expectation, the facial features that correspond with strength, dominance, and masculinity in males (a large interbrow and intercanthal distance, thin, high eyebrows, and a narrow mouth) are actually, not those rated as attractive by females (Windhager et al, 2011). Rather, decreasing the interbrow distance (or gap between the eyebrows) is considered more attractive in men. This study shows definitively that although a short eyebrow gap may make a man appear more feminine, more subordinate and less strong, that is what female’s rate as more attractive. Though this finding, baffles common biological assumptions about sexual selection, it is widely corroborated by many other studies (Cunningham et al, 1990 : Swaddle & Reierson, 2002 : Schaefer et al, 2009).