When staring longingly at your significant other, your brain is pumping out drug-like opioid chemicals to reward you for finding a mate, say Norwegian scientists.
Visual information about others, specifically faces, plays a valuable role in human mate selection and bonding, and activates the same brain reward systems as food and money do.
Researchers conducted a study which found that boosting the opioids in men’s brains made them look at images of women for longer, and rate them as more attractive.
“Facial attractiveness is a powerful cue that affects social communication and motivates sexual behaviour,” the researchers write in the journal Molecular Psychiatry.
“Attractive people are both judged and treated more positively, reﬂecting the biased stereotypical notion that ‘beautiful is good’.”
Thirty healthy men were asked to view photographs of female faces and rate them according to an aesthetic evaluation (liking), and motivation for viewing (wanting).
When given morphine – which increases opioid receptor activity – the men gave the most attractive faces a higher average rating.
And they viewed the faces they found more attractive for a longer period of time, while opting to change the picture more quickly if they found it unattractive.
Alternatively, men who were given a opioid suppressor called naltrexone showed both reduced ‘liking’ and ‘wanting’ behaviour.
They did not rate the most attractive faces as high, and did not want to view the most attractive faces for as long.
The authors note that the opioid manipulations had a more pronounced effect on viewing the most attractive women, which in evolutionary terms, are the most valuable.
They suggest that the human opioid system may play a role in social motivation by intensifying the rewards of the most valuable stimuli, while inhibiting the desire for less valuable social cues.
The study, Rewards of beauty: the opioid system mediates social motivation in humans, by Olga Chelnokova of the University of Oslo and colleagues, is published today in the journal Molecular Psychiatry.
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