This was another surprise. I had thought that people with a higher number of friends would change their profile pictures more frequently to keep their audiences entertained. Again, however, most of the 'action' takes place from between 400 and 1000 friends. It is also rare for either gender to change their profile picture more than 5 times a year. My new theory: I would have to analyze the amount of posts people share, photos they upload, videos they share, and so on in order to get a better understanding of whether Facebook account holders do what they do to get and keep the attention of other friends. A profile picture might be too broadly broadcast throughout Facebook, and thus require a timely and careful selection and editing process, to frequently change.
Maybe, however, Facebook selfies are more for the person than the audience. It is his or her little self-contained, perfect vision of him- or herself.