How do we know about the internal lives of other people?
First, most importantly, we have to assume that they are similar to our own inner lives. This means that we see the world as much more homogeneous than it actually is because our own experience can only ever be one data point. On the other hand I talk about my inner life pretty often and other people are often surprised–am I calibrating my expectations correctly? Or are the reactions systematically tilted one way or the other?
Second, we get some sense of other people’s inner lives from reading–especially novels–and from conversation. There is a large selection effect–we only know about the inner lives of introspective people. This is troubling, since many people are not introspective. Though it’s quite hard to distinguish between people who are not introspective and people who just don’t talk about this stuff. This gets to the larger point of this post–what would it even feel like to not be introspective? Our only idea is from those times in our own lives when we don’t feel introspective.