Rational camp always question the validity of behavioral arguements: first is arbitrage; and then learning. Here is something I felt kind of fun to read.
How Basic Are Behavioral Biases? Evidence from Capuchin Monkey Trading Behavior
M. Keith Chen, Venkat Lakshminarayanan, and Laurie R. Santos
http://www.journals.uchicago.edu/JPE/journal/contents/v114n3.html