It is interesting to see bimodal distributions in real life where the cause of such a distribution can be guessed at a priori. One place where I stumbled on this recently is in the imdb user ratings of films.
For instance, the ratings distribution for a typical film shows a typical bell distribution: see Courage Under Fire for instance. But take new recent polarized offerings: An American Carol and Religulous. These show a clear bimodal distribution where the modes are at the extremes. Then I started looking for a film where the polarization is not as extreme as in the above two.
It appears trimodal distributions are more common than bimodals: Lady in the Water, The Chronicles of Narnia, Titanic, Borat. Could not predict a film which has a clean, non-extreme bimodal distribution. The closest I could get to was Blue Velvet. What does this (anecdotal, non-exhaustive) experiment signify? That we are prone to go overboard; we are more likely to vote when we belong to the fringes. Scary?
