The Underdog

Over at Slate, Daniel Engber has a fascinating (and thorough) investigation of why we root for the underdog. There are numerous factors at work, from the availability heuristic to our deep desire for equality. But I was most intrigued by this research, which tries to explain why we associate underdogs with virtuous characteristics, like effort and teamwork:
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The irony is that it remains unclear whether underdogs actually try harder. For instance, last month I wrote about the superstar effect, which suggests that golfers playing against Tiger Woods played significantly worse. Jennifer Brown, an applied economist at Northwestern who performed the analysis, argues that this is due to reduced motivation and effort:
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In other words, underdogs who really believe they are underdogs - and know that they probably won't win - are less likely to put in the required effort. Why waste blood, sweat and tears on a probable loss? If that's the case, then the coaches of underdog teams play an extremely important role in helping to counteract the superstar effect. This guy deserves a raise.
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But there is one group that seems resistant to the underdog bias: referees. In fact, it seems that referees are easily swayed by the emotions of the crowd, which is why they tend to give better calls to the team with home-field advantage.