Behaviourist Explanation to Abnormality

Explains how behaviour is learned through stimulus-response associations. An event in the environment (stimulus) results in a psychological reaction (response). 
 Watson & Raynor (1920) 

Before Conditioning:
Loud Noise (UCS) - Fear/Crying (UCR)
White Rat (NS) - No Fear Response

During Conditioning:
Loud Noise (UCS) + White Rat (NS) - Fear/Crying (UCR)

After Conditioning:
White Rat (CS) - Fear/Crying (CR) = PHOBIA 

Applying classical conditioning to the explanation of phobias:
Fear of heights: if a person goes to the top of a high building (UCS) and they feel dizzy and sick (UCR) they associate high places with the feeling of nausea (CR). This then lead to vertigo.

Skinner(1974) explains that behaviour is influenced by the consequences of our actions in terms of positive and negative reinforcement. 
Positive = encouraging behaviour through reward. e.g. If a friend is unhappy, we give them something to cheer them up such as taking them out or buying them things. Negative = encouraging behaviour by taking away unpleasantness. e.g. If a child is naughty and they get grounded, but they tidy their room, so you let them off. 

Operant conditioning can explain some psychological disorders as antisocial personality disorder:

If childhood agression is reinforced then the behaviour is likely to be repeated. Also, anxiety or depression might receive reward in the form of attention and concern, also making the behaviour be repeated.

Bandura suggests that if we observe behaviour, are able to recall the details, have the ability to replicate it and the opportunity to, then if we are motivated by reinforcements, we will imitate and repeat it. 

Anti-social behaviour can also be explained by SLT if a child observes a model who is rewarded. This can lead to imitation. Also some phobias develop due to observing how a model responds to a stimulus.