Smiling makes you more attractive.
A new study has found that giving the camera a grin actually makes you appear more alluring to other people.
Experts recruited 112 volunteers and presented them each with 80 pictures of people who were either smiling or had a neutral expression.
Asked to rate the faces that were more attractive, the participants gave higher scores to those who had a smile on their face.
Dr. Christian Valuch, who led the study for the University of Vienna, said: "People always had straight faces in Victorian photographs, and in the 1990s it again became fashionable for supermodels and celebrities not to smile - if they wanted to appear cool.
"But these results suggest people look more attractive when they are smiling.
"It is a facial expression we are drawn to, because it makes people look friendly, approachable and non-threatening.
"So when you are told to smile for the camera, you probably should."