Selfies - pictures people take of themselves - have been one of the big talking points of 2013.
"Selfie" was even named "word of the year" by the Oxford English Dictionary.
But what does the phenomenon say about the people who take them, and about society in general? #BBCtrending speaks to two experts - Lisa Orban and Andrew Przybylski - about the psychology of the selfie.
Do you take a lot of Selfies?
What did you think about what the two experts had to say?