Seemingly-harlmess selfies which clog up your social media newsfeed could actually be a sign that your friend has a more sinister problem, according to a new study.

Men who post many photos of themselves online scored higher on tests measuring narcissism and psychopathy, while those who edited those photos self-objectificatied more and had stronger narcissistic tendencies, according to researchers.

Jesse Fox, lead author of the study and assistant professor of communication at The Ohio State University, stressed that the results do not mean that men who post a lot of selfies are automatically narcissists or psychopaths.

Rather, the men who took part in the study all scored within the normal range of behaviour – but with higher than average levels of these anti-social traits.

To make their findings, researchers analysed data from an online survey completed by 800 men aged between 18 and 40.

Participants were asked how often they posted photos, whether they edited their photos before posting - by cropping, adding filters and or using picture-editing software. They also completed standard questionnaires for anti-social behaviours and for self-objectification.

According to the study, those who posted more photos showed signs of narcissism and psychopathy, but psychopathy was not related to editing photos.

"That makes sense because psychopathy is characterised by impulsivity. 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," Fox explained.

Editing photos was also related to higher levels of self-objectification, which has been rarely studied in heterosexual men, Fox said.

"We know that self-objectification leads to a lot of terrible things, like depression and eating disorders in women," she added.

"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."

Fox explained the study does not include women because the dataset received from a magazine did not have comparable data for women. But Fox said she is currently conducting follow-up work that suggests the same findings found in this research also apply to women.