From typicallyspanish.com

Spanish Oddities
Strange named Spaniards are more likely to be rich
By h.b.
Oct 2, 2008 - 5:43 PM

A study carried out by the Carlos III university in Madrid, ‘Surnames and Social Status in Spain’, published today, has shown that professions considered to be of greater prestige have professionals with less common surnames.

The researchers attribute the findings to what has been a relatively low social mobility level in Spain, and say that people with common surnames find it more difficult to reach upper social circles.