Before that, children genuinely cannot conceive that another person holds a different belief. It’s called Theory of Mind, and its arrival is one of the most dramatic cognitive leaps in human development.
The wild part? Some of us never fully develop it.
And those who do still switch it off under stress — reverting to the assumption that everyone sees what we see, wants what we want, fears what we fear.
Every argument that ever escalated? Probably this.