He published the book "On The Origin Of Species" which states the Theory of Evolution, which can be applied to Psychology because it allowed scientists to study animals and relate them to human behavior.
His theory integrates a continuous interaction between behaviors, cognitions and the environment. Bandura’s work is considered part of the cognitive revolution in psychology that began in the late 1960s.
Pavlov's discovery of conditioning remains one of the most important in psychology's history. In addition to forming the basis of what would become behavioral psychology, the conditioning process remains important today for numerous applications, including behavioral modification and mental health treatment. Classical conditioning is often used to treat phobias, anxiety and panic disorders.
In 1959, Chomsky published an influential critique of B.F. Skinner's Verbal Behavior, a book in which Skinner offered a theoretical account of language in functional, behavioral terms. He defined "Verbal Behavior" as learned behavior that has characteristic consequences delivered through the learned behavior of others.
His most important contribution concerns the inter-relationship of language development and thought. This concept, explored in Vygotsky's book "Thought and Language" establishes the profound connection between speech, and the development of mental concepts and cognitive awareness.
Skinner contributed the theory in which we are supposedly controlled by whatever our environment forces us to be. Essentially, we are what we live in. In 1974, he published About Behaviorism as a response to the misrepresentation and lack of understanding in his work.