Last month, Ovul Sezer, Francesca Gino, and Michael I. Norton of  Harvard Business School posted Humblebragging: A Distinct – And Ineffective – Self-Presentation Strategy to SSRN (available here).  

Here is the full article abstract: 

Humblebragging – bragging masked by a complaint – is a distinct and, given the rise of social media, increasingly ubiquitous form of self-promotion. We show that although people often choose to humblebrag when motivated to make a good impression, it is an ineffective self-promotional strategy. Five studies offer both correlational and causal evidence that humblebragging has both global costs – reducing liking and perceived sincerity – and specific costs: it is even ineffective in signaling the specific trait that that a person wants to promote. Moreover, humblebragging is less effective than simply complaining, because complainers are at least seen as sincere. Despite people’s belief that combining bragging and complaining confers the benefits of both self-promotion strategies, humblebragging fails to pay off.

Although the authors accurately explain that humblebragging is "bragging masked by a complaint,"  I am partial to the Urban Dictionary definition:

Subtly letting others now about how fantastic your life is while undercutting it with a bit of self-effacing humor or "woe is me" gloss.
 
Uggggh just ate about fifteen piece of chocolate gotta learn to control myself when flying first class or they'll cancel my modelling [sic] contract LOL :p #humblebrag

I think most of us know someone who is a user of the humblebrag.  I used to think it was just a fairly common technique among lawyers and academics, though I am now more of the mind that it is a "people" thing, with lawyers and academics perhaps leading the way.  I'm rather glad to see an article that shows that humblebragging is empirically ineffective in its goals.  In my experience, I have also found that it's also not especially effective in getting people to like the humblebragger, either.  

Now, if only blatant, unrepressed, old-school bragging weren't so effective in some circles. we could make some real progress.