More from Michael Shermer’s How We Believe…

The average number of individuals in self-organizing groups is around 150. This is based on various and sundry anthropological data.

It is the maximum number of people, on average, that we can comfortably “know” and care about (your individual mileage may vary). It covers people “you would not feel embarrassed about joining uninvited for a drink if you happen to bump into them in a bar.”

There are numerous implications of this, I should think, but one interesting thing the author noted is that through the miracle of modern media, our Pleistocene brains are tricked into including celebrities in this group. Because we learn so much about them, we get the feeling we know them.

So, does that mean our 150 person quota gets dinged down for every celebrity we follow? What about online relationships? If your Friends list is ticking up towards 150… do you start forgetting who your mother is and what kind of foods she likes?

Be wary.