(Reuters)
Updated: 2007-09-19 16:05

Disbelievers in love at first sight may have to think again because new research shows it only takes half a second to decide if someone is attractive and a potential mate.

"The study gets at the basic perceptual aspects in mating," said psychologist Jon Maner, of Florida State University, who headed the team.

"It shows how quickly, strongly and automatically people are attuned to physical attractiveness whether looking for mates or guarding their mates from potential rivals," he added in an interview.

Maner and his team, who published their findings in the Journal of Personality and Social Psychology, discovered that people tend to fixate on attractive faces within the first half-second of seeing them before sizing them up as a possible mate or rival.

In the study university students were shown pictures of very attractive or average-looking people for one second before being asked to look at something else. By measuring people's reaction time, Maner and his team were able to determine that half a second is all it takes to decide if someone is attractive.

The researchers also noticed that people fixated on attractive faces for half a

second longer after the one second time limit.

Single people in the study were interested in members of the opposite sex.

"These are the kind of people we might prefer as romantic partners, but it doesn't mean we'd be able to have a relationship with them because highly-attractive people are very sought after," said Maner.

But people in committed relationships who viewed the pictures were interested in attractive members of the same sex.

"These are the type of people we are jealous of and vigilant towards, worrying about infidelity as we try to guard our mates," Maner explained.

The study also showed the pitfalls of visual fixation, including negative effects on self-esteem when looking at an attractive person of the same sex. Maner said the negativity could potentially be linked to illnesses such as bulimia.

Another pitfall is that people may become less satisfied in their current relationships.

"The evidence shows when we see attractive alternatives to our partners it can make us feel less satisfied and less committed with our current partner, which clearly has implications for relationship success," said Maner.