Anyone who's taken a selfie knows it can be hard to find the right camera angle.
But it turns out there is no one perfect angle - it all depends on what you're trying to achieve.
Scientists in Germany recently decided there hasn't been enough research into the selfie craze, despite millions being taken every day.
"Taking selfies is a well-known but still poorly investigated social phenomenon," the study, published earlier this month in Frontiers of Psychology, begins.
"It is assumed that taking selfies has now become an important social phenomenon for expressing individual values and personality traits, showing off and sharing the current mood. Despite the high degree of relevance, there is only sparse research that has investigated whether selfies and related self-portraits serve as a valid predictor for personal traits."
That is, can you tell if someone's attractive from their selfie alone? Or intelligent?
The researchers asked 172 people to rate selfies on a number of criteria, including attractiveness, helpfulness, intelligence and how much they think the subject weighed.
Each subject was presented not only in a front-on selfie, but also at different angles above and to the side.
Attractiveness: The most attractive selfies were taken at a 15 degree angle, showing the left-hand side of the face - the effect especially pronounced for women.
Intelligence: Selfies showing the right-hand side of the face were rated as more intelligent, when compared with front-on selfies. They were also rated more sympathetic, particularly in men.
Helpfulness: Selfies taken from above made people seem helpless.
"You may expect that smaller persons indeed rely on the helpfulness of the respective leader instead of being more helpful themselves," the study notes.
But oddly, participants didn't rate selfies taken from below as making the subject seem more helpful.
Body weight: Perhaps the least surprising finding of the study was that selfies taken from below, making the subject look bigger, also made them look "significantly" heavier. The reverse held for selfies taken from above - especially for those showing their right cheek, rather than left.
"Faces seen from a higher viewing perspective are associated with a significantly lower body weight compared to faces seen from a lower viewing perspective."
So there it is. If you want to look skinny, hold the camera high and to your right. Intelligent, hold it to your right, at head height. Attractive, snap from the left.