The behavioural model concentrates only on behaviours and the responses a person makes to their environment, these can be external or internal. Behaviourists have tended to focus their attention on the role of external events and behaviours as these are more observable and therefore make gaining results easier. This means that not all aspects of abnormality are considered, a weakness of the approach as it is selective in its research. To gain a full understanding of behaviour all features would have to be monitored, it is easy for patients to show demand characteristics when being observed especially if only external behaviours are studied.
Research has not always supported the approaches claims. For example, conditioning theories of the acquisition of fear would struggle to explain why many people are unable to identify an incident in their past which led to traumatic conditioning. It also does not offer an explanation for why humans have certain fears ingrained about relatively harmless things and are perfectly comfortable with things that could potentially be harmful such as moving traffic.
Abnormal behaviour is no different from normal behaviour in terms of how it is learned. The approach suggests that abnormal behaviours are learned through conditioning or social learning as well behaviour is determined by external events. The principles of learning theory can be used to explain many disorders for which the major characteristics are behavioural. An example of this is arachnophobia which involves avoidance, an external symptom and feelings of anxiety when in the presence of a spider, an internal symptom.
In order to experiment features such as those considered by the behavioural approach it is likely that mostly laboratory studies and observations would be used to control extraneous variables that could affect the patient’s reactions. Because of this, ecological validity is reduced...