Income disparity precedes depressions?

According to a recent WSJ Article Richest Americans See Their Income Share Grow, the richest 1% of Americans pulled in the highest share of gross income since 1929, at around 22% of the nation's total.  So if that also happened in 1929, is that bad sign for things to come?  In the old days, a rich noble class led to revolutions.  Now do we just have economic revolutions?