Human nature, testosterone, and compensation structures that encouraged deceptive practices are, more or less, the factors that contributed to the misbehaviour of financiers prior to the financial crisis, according to a recent paper from Birkbeck College in London.

Author of the paper Anne Sibert's theories were posted this week to the VoxEU blog, which put forth her ideas for why financiers "behaved in such an egregious fashion" http://tiny.cc/VhEoH.