In a firm in Kenya workers from different ethnicities had to work in the same group. When they were getting paid according to individual production, they would sabotage those of different ethnicities, leading to lower productivity. When the payments were based on the production of the whole team, sabotaging decreased and overall productivity rose.
Hjort (forthcoming) Quarterly Journal of Economics
People cooperate more when they are shown a message containing a moral statement. However this effect is permanent only when it is also possible to punish those who do not cooperate.
Dal Bo & Dal Bo (2014) Journal of Public Economics
Sadness makes people less willing to take risks. On the other hand, anger increases risk taking.
Campos-Vazquez et al. Journal of Behavioral and Experimental Economics (2014)