When we talk about other people, we are often talking about ourselves

From Tyler Cowen in Discover Your Inner Economist. h/t Gretchen Rubin.

To get a person’s real opinion, ask what she thinks everyone else believes… If people truly hold a particular belief, they are more likely to think that others agree or have had similar experiences.

For instance, if a man has had more than thirty sexual partners, he will more likely think that such behavior is common. After all, his life is one ‘data point,’ and that data point presumably weighs heavily in his mind. Furthermore the man with more than thirty partners probably knows a higher percentage of other people with thirty partners or more. This will further encourage him to make a high estimate of how many partners other people have had…

[People] tend to assume that other people have had life histories at least somewhat similar to their own. When we talk about other people, we are often talking about ourselves, whether we know it ourselves.