The difficulty of knowing other minds is why the technique of introspection was replaced with more objective measures by the early

The difficulty of knowing other minds is why the technique of introspection was replaced with more objective measures by the early "behaviorists".

Introspection is the examination of one's own conscious thoughts  and emotions. In psychology it refers to the procedure which depends solely on perception of one's psychological state, while in an otherworldly setting it might allude to the examination of one's spirit.

Old telephone. is prehistoric object