If you have ever wondered why people look more attractive and beautiful to you after you have had a bit of booze, it is all because of the bilateral symmetry.
It is thought that humans and other organisms have a strong evolutionary preference for the appearance of symmetry, and this means people who are considered attractive are often those who display a high degree of bilateral symmetry, reports io9.
According to NCBI ROFL report, researchers at London's Roehampton University hypothesized that a reduced ability to judge this symmetry brought on by the general visual impairment of alcohol might well account for the phenomenon that people seem more attractive when one is drunk.
Sixty-four students underwent the study and were classified as either sober (control) or intoxicated with alcohol.
The experiment tested the hypotheses that acute alcohol consumption decreases ability to detect asymmetry in faces and reduces preference for symmetrical faces over asymmetrical faces. Twenty images of a pair of faces and then 20 images of a single face were displayed on a computer, one at a time.
The study found that sober participants had a greater preference for symmetrical faces and were better at detecting whether a face was symmetrical or otherwise, supporting the hypotheses. A further, unexpected finding was that males made fewer mistakes than did females when determining whether individual faces were asymmetrical.
The reduced ability of inebriated people to perceive asymmetry may be an important mechanism underlying the higher ratings of facial attractiveness they give for members of the opposite sex and hence their increased frequency of mate choice.