Friends have similar brains

Another interesting psychological study, as summarized in the NY Times ("You Share Everything With Your Bestie. Even Brain Waves"). They asked a class of students how closely they felt connected to each of their fellow students. And then they showed them film fragments and measured how their brains reacted to them. Similarity proved to be a good guide to who were friends and how close. Of course one shouldn't put too much in this research. They found correlation. But that doesn't mean that that there can't be exceptions. So one might investigate whether there are people who are similar who are not friends - and why. One might also look whether all kinds of traits worked similarly: does having the same sense of humor work the same as being interested in the same fields of science?