Footballers, film stars and other men addicted to posting selfies on social media are displaying psychopathic traits, according to a new study.
They are more likely to be narcissistic, impulsive and display other anti-social characteristics such as a lack of empathy, said university researchers.
The findings could shock many famous men who cannot resist posting pictures of themselves on sites such as Instagram, Twitter and Facebook.
But although such actions are associated with psychopathy, it does not mean the vain men are about to go on a murderous rampage.
Instead, it means they score higher than average levels for anti-social traits, Ohio State University researchers told the specialist journal Personality and Individual Differences.
Those who edit their own pictures to make themselves look better show signs of narcissism and self-objectification, said assistant professor of communication Jesse Fox.
The study said narcissism is most commonly associated with vanity, but as a psychological flaw relates to a feeling of being more intelligent, attractive and better than others.
Men who put their pictures online as soon as they can are more likely to show signs of psychopathy, defined as having a lack of empathy or regard to others and impulsiveness.
Researchers conducted tests on 800 men aged 18-40 who completed a survey on their social media output alongside psychological questionnaires to establish personality traits.
It asked them about posting pictures on sites such as Instagram and Twitter, whether they were Photoshopped first or posted without editing and how often.
Ms Fox said: “It’s not surprising that men who post a lot of selfies and spend more time editing them are more narcissistic.
“The more interesting finding is that they also score higher on this other anti-social personality trait, psychopathy, and are more prone to self-objectification.”
She added: “Most people don’t think that men even do that sort of thing, but they definitely do.”
Men showing signs of psychopathic behaviour were those who did not take time to carefully edit their photos before posting them.
“Psychopathy is characterised by impulsivity,” she added. “They are going to snap the photos and put them online right away.
“They want to see themselves. They don’t want to spend time editing.”
Such behaviour can lead to further problems, suggested the author of the study.
She added: “We know that self-objectification leads to a lot of terrible things, like depression and eating disorders in women.”
“With the growing use of social networks, everyone is more concerned with their appearance. That means self-objectification may become a bigger problem for men, as well as for women.”