If you've ever had one too many and tumbled into bed with a vision, only to be greeted in the morning by a sight you'd gnaw off your own arm to escape, take heart. It won't make the memory any less painful, but you can take comfort from the fact that there is now academic underpinning for the effect known commonly as "beer goggles".
In scientific terms, even a little alcohol reduces the ability to assess facial symmetry, which plays a key role in attractiveness and human mate selection.
The effect is particularly pronounced in women, with female drinkers less able to distinguish between attractive and not so attractive men after just a couple of vodkas.
Facial symmetry, where one side of the face mirrors the other, is thought to have evolved as a mark of attractiveness as it signifies good genes. Both sexes select outward signs of genetic quality to ensure better offspring. Ratings of attractiveness in the opposite sex are highest when symmetry is at its greatest, research has shown. It's also known that attractiveness rises when people have had a drink or three: the beer goggles effect.
But that's not the whole story. It turns out, you can get "beer goggles" without imbibing any alcohol at all.
Psychologists led by Laurent Begue at the Pierre-Mendes France University in the southeastern city of Grenoble carried out an unusual experiment in a local bar and then in laboratory conditions.
In the first stage, 19 drinkers, two-thirds of them men, were asked to assess their attractiveness on a scale of one to seven. Their alcohol levels were measured by a breathalyzer, and true to form, the higher the amount of booze that had been drunk, the rosier the self-assessment.
In the second phase, 94 men were invited to taste-test a new fruit cocktail on behalf of a research firm that was in fact a bogus company set up for the purposes of the experiment. They were told that half of the volunteers would be given an alcoholic version of the cocktail and the others would be given a non-alcoholic version. No one knew which was which.
They were then asked to write and deliver a filmed message that was supposed to be used in advertisements for the new "brand." Each volunteer was asked to watch his film and rate his own performance for attractiveness, brightness, originality and humour. Their alcohol concentrations were measured - the levels ranged from zero to twice the legal drink-driving limit.
But the data showed up a curiosity.So save your money and buy her a non-alcoholic drink while her back is turned...
Those who believed they had drunk alcohol gave themselves high self-assessments, regardless of whether they had imbibed any booze or not. And those who had believed they had not drunk any alcohol gave themselves a low assessment, even when there had been a hefty shot of pure alcohol in their drink.
Thanks to Wombat-Socho at The Other McCain for getting his Rule 5 (Lobo Town) list together on such short notice after vacation.