Rats fall victim to peer pressure

Social learning and conformity in brown rats

New Scientist vol 198 no 2655, 
May 10 2008 p18

Humans and chimps are known to have a strong urge to conform, and this is also true of brown rats. Bennet Galif and Elaine Whiskin, from McMaster University, Hamilton, Ontario, have discovered that rats which initially did not like food tasting of cinnamon will eat it if they meet rats that have eaten cinnamon-flavoured food. The rats were fed food tasting of cinnamon, then injected with a chemical that produced nausea. After that, the rats chose food tasting of cocoa. However, after meeting rats that had eaten cinnamon-flavoured food, and so smelled of cinnamon, the rats went back to eating cinnamon-flavoured food. The researchers say that this raises the question of why animals conform, despite knowledge from their own experience.