Ethical issues
Strengths:
Biological-
The strength of this is that modern scientific technology can be used to scan or measure biological processes that used to be undetectable. A good example of this is brain scanning technology like the MRI or PET scans. Biological explanations often lead to the invention of drugs or surgical procedures that can help people with psychological problems; for example, Prozac is a drug which boosts serotonin levels in the brain to combat depression.
Cognitive-
On the other hand, this approach can be reductionist because it assumes people make up their minds about things in isolation, whereas in fact they are affected by other people, by biological factors and maybe by unconscious urges they're not even aware of. Cognitions usually have to be studied through self-reports, which have a lot of problems of their own.
Developmental-
The strength of this is that it studies the early beginnings of behaviour and might give us insights into how to encourage or discourage behaviour in the future, through education, parenting or interventions. For example, if children can be helped while young they might never turn to crime or might go on to be great athletes.
Individual differences- The strength of this is that it keeps the focus on the individual when psychologists are often inclined to make sweeping statements about large populations. It also reminds us of the importance of unusual or eccentric cases - that they "Everyman" doesn't covery everybody. This is why psychologists of Individual Differences like to use case studies and collect qualitative