People whose profile pictures mainly depicted themselves seem to have the widest range of Facebook friends, from <100 to a few thousand. People whose profile pictures depicted themselves alongside friends or others appear to have a number of Facebook friends ranging from ~750 to ~1125. This deviates from expectations that those with more people featured in their profile pictures would have more Facebook friends (or the converse), perhaps due to a correlation between these numbers and the general social inclinations of the subject. 

Not everyone's number of Facebook friends was available for me to see, most likely due to privacy settings. An interesting point to note is that those with such settings were exclusively female. Five had non-photo representations of themselves, or of other abstract subjects. Of these, only one was male. The sample size is clearly small and unrepresentative of the general Facebook user, but I wonder if these suggest a gender trend with regards to privacy-consciousness and inclination towards anonymity.

I was interested in trying out this analysis of Facebook profile pictures (on the number of Facebook friends one had, or general friendliness of a person compared against the people in their profile pictures) because I did think that having others in one's profile picture indicated popularity among one's social circle, or generally reflected how social one was (and therefore how many Facebook friends one would have). A brief search on Google revealed more joke/humour articles on how one's Facebook profile picture relates to one's personality (usually derogatory or insulting), followed by other small articles with some semblance of academic attitude. Here are some links: