"Plurality is not to be posited without necessity" says one of the major rules of scientific thinking - The Occam's Razor . In other words when we have two explanations of the same evidence the one that is less complicated (or require fewer assumptions) is more likely to be true. Of course it is rarely the case that the models we are considering are explaining the data to the exact same extent, but modern statistical techniques have been developed deal with this (see BIC , AIC and Bayes factor ). In short, those methods combine evidence for each model (such as goodness of fit or likelihood) with complexity of the said model (for example the number of free parameters) in a way that penalizes overly complex solutions. All of this should be nothing new to anyone dealing with models, data, and theories. There is, however, one additional aspect concerning the complexity of explanations - a social one. We intrinsically like simple stories. It's not only because it is...
Brains, behaviour, statistics, and random thoughts.