Fascinating. Experimenters at Stanford were looking at the difference between "exhilarating" conflict and "exhausting" conflict -- and they found..
In a new paper, three researchers demonstrate that whether conflict is exhausting or exhilarating depends on what is really threatened in the dispute. A threat to a relationship is most likely to leave one exhausted (and susceptible to the temptation of chocolate) while threats to tangible interests such as safety or property, or elements of an individual’s identity (such values or ideologies), energize people to take action and fight back.
It's a little bit on the academic side, but the whole article is worth reading. Don't forget to come back here for the discussion --
http://www.kellogg.northwestern.edu/News_Articles/2012/ready-for-chocolate.aspx