We don’t need a theory to know that we’re each distinctive and apart.
It’s back to the theory of self for us.
In part, the resistance encountered by human sociobiology, Darwinian psychology, evolutionary psychology—call it what you will—may reflect that none of the “ultimate” interpretations thus far offered account for the enormous amount of (perceived or actual) individual variation that human beings identify among themselves. Perhaps there is something about the human psyche that believes a theory of individuality will do insufficient justice to our own deeply cherished individuality
Here’s the thing: there’s a relatively standard variation to human behavior because the inputs are within a fairly predictable range. Something does that — culture, nature, nuture — and creates the predictability that generates a familiar response among groups of people.
But every person is alone with the voices in their head. Their perception is unique and new, in each instance, a creative act of seeing and interpreting. That aloneness makes us individual, discrete.
One fanciful theory about the neandertals was that they communicated through a kind of group mind meld that rendered language unnecessary.
We don’t have the sanctuary of a group mind meld. Doesn’t that give us all we need to understand what is means to be an individual?