That changes for most kids at around age 3 or 4, when they develop theory of mind.
Based on this research, he developed a new theory of weight control.
I'm beginning to develop a theory, and I'd like to check it with him.
I'm the one who developed the theory your new toy is based on.
Now please go back to square one and develop the theory that was put forward in 1880.
Different people may develop more, or less, effective theories of mind.
While you were on your way here, I developed a preliminary theory.
The Shadow would take another course, to develop a theory of his own.
He developed his theory of telephone traffic over several years.
From this starting point he has developed a theory of social categories.