Science has finally revealed the mystery of why we automatically close our eyes to kiss - and it has nothing to do with romance.
Dispelling the notion we close them out of reverence, passion, or even because we can't focus so close up to another person's face, Royal Holloway University psychologists say it's because humans simply can't deal with the sensory overload.
Their research found that even accomplished multi-taskers are unable to simultaneously process visual data and a physical sensation such as kissing.
“Tactile awareness depends on the level of perceptual load in a concurrent visual task,” study leaders Dr Polly Dalton and Sandra Murphy explain.
For the study, they measured how easy it was for people carrying out visual tasks to feel something touching their hands. As the visual tasks became trickier, the participants' ability to detect touch declined.
“If we are focusing strongly on a visual task, this will reduce our awareness of stimuli in other senses,” Dr Polly Dalton tells The Sunday Times. “It is important for designers to be aware of these effects, because auditory and tactile alerts are often used in situations of high visual demand, such as driving a car or flying an aircraft.”
She says that people often prefer to shut their eyes in situations when tactile sensations trump the visual, such as dancing, reading braille, kissing or having sex.
“These results could explain why we close our eyes when we want to focus attention on another sense,” Dr Dalton says. “Shutting out the visual input leaves more mental resources to focus on other aspects of our experience.”
The study was published in the Journal of Experimental Psychology: Human Perception and Performance.