The origins of Cognitive Behavioural Therapy (CBT) are rooted in behaviourism, which tends to view human behaviour as reactive.
In other words, humans react to external stimuli to satisfy needs and wants.
Behaviourism proposes that we are conditioned to behave in certain ways by either continual reward or continual punishment of certain actions that we engage in. It assumes that the brain is a blank canvass at birth which makes it easy to influence.
This conditioning was manifest in many experiments involving animals, e.g. monkeys, dogs, rats, probably the most famous being the Pavlov’s Dog experiment where a dog salivated on hearing a bell it associated with food.
It was further developed by the psychologist B. F. Skinner and others who gave it a fancy name; Operant Conditioning in the early decades of the 20th Century and thereafter became very popular in the world of psychology.
Behaviourism, or operant conditioning, is, of course, a very seductive model in terms of getting people to conform to society’s norms and expectations.
It is true that we are conditioned to behave in certain ways by experiencing punishment and/or reward.
It seems to make sense, and fits in with our general experience of the world.
Looking back now, it can be said that behaviourism was a phase in the evolution of methods of helping people in distress and was a stepping stone on the road to CBT [1]
[1]. Here is a brief history of CBT if you are interested.