Skinner was one of the founding fathers of behavioral psychology. He felt strongly that all human behavior could be broken down I a fundamental electro-chemical interaction. This was groundbreaking in psychology for a number of reasons: 1- it gave rise to “scientifically respectable” psychological research, 2- it crossed some philosophical boundaries into concepts of free will, 3- it laid foundation for cognitive behavioral therapy, by making the correlation between conditioned behavioral response and positive/negative reinforcement. (He wasn’t the only one, Pavlov being the other of note, but he was one who gained recognition.)
His theories have come to be known as “incomplete,” as we discovered there are other measurable elements that predict behavior, but his steadfast belief in his ideas, and his committed research brought on a whole new wave of psychological ideology.