Bio A Strength 1
One strength is in the value of the applications of the biological approach (Bio A). Therapies such as chemotherapy, which alter the level of neurotransmitters to change behaviour, now enable many people to live in the community rather than in hospital. For example, Viguera (2000) found a success rate of 60% for bipolar patients taking Lithium. This suggests the Bio A is strong as it has improved the quality of peoples lives.
Bio A Strength 2
A second strength is the Bio A is helpful as it throws light on the nature-nurture debate. Biological research suggests that behaviour is not shaped by environmental factors such as learning, but that nature plays a significant role. For example, Selye's GAS sees stress as a set of biological responses to a stressor. This suggests the Bio A is strong as it provides an important counter balance to approaches which emphasise nurture.
Bio A Weakness 1
One weakness of the Bio A is that it is deterministic. This means it sees behaviour as shped by inborn physical forces over which the individual has no control. For example, differences between males and females are seen as due to differences in the brain and hormone system. In the Reimer twin study, "Brenda" revented to being "Bruce" as biological sex appeared to over-ride upbringing in shaping his/her gender identity. This suggests the Bio A is weak as it claims that individuals have no free will and cannot change, which is a very pessimistic approach to behaviour.
Bio A weakness 2
Another weakness is that the Bio A is reductionist. This is because as beng due to biological factors such as genes and brain chemicals and it fails to take other factors into account such as learning and the unconscious mind. For example, psychologists who see IQ as natural tend to neglect the importance of improving housing and schoolinng in order to raise IQ. This suggests the Bio A is weak as it explains behaviour in an oversimplified way.