Biological approach in Psychology

PSYB4

Approaches:                                    Biological Approach

AO1 basic assumptions:

1.  Extreme NATURE approach- human behaviour is strongly influenced by our genetic makeup (inherited genes)
2.  Central nervous system (especially brain) is essential for thought and behaviour to take place. Therefore an understanding of brain structure and functions can help explain behaviour and thought. Brain and mind are considered the same thing, therefore all thoughts/ feelings have a biological cause.
3.  Chemical processes in the brain are responsible for psychological functioning and an imbalance of chemicals may cause mental disorders (eg. low levels of seratonin can result in depression)
4.  Humans have evolved biologically through Darwinian evolution- much in common with other animals, especially those close to us on the ‘evolutionary tree’ therefore studying animals can tell us a lot about development of human behaviour.

Genetic basis of behaviour

Genotype= Your actual genetic makeup, represented in your 23 pairs of chromosomes. Each person has a unique genotype (except identical twins)

Phenotype= Actual expression of your genetic makeup. (includes things like height and eye colour, also behavioural and psychological characteristics)

Genotype is FIXED. Phenotype can be ALTERED however by environmental aspects.

EXAMPLE- Phenylketonuria (PKU) is an inherited disorder where proteins are not processed properly; leaving a poisonous substance in the blood that causes brain damage. If the condition is detected early, it can be controlled through diet which stops brain damage.

Here, the genotype is the disorder which causes brain damage, however the phenotype (expression of PKU) depends on the diet of the sufferer. 

Autonomic Nervous System

The autonomic nervous system transmits information to and from internal organs to carry out life processes (breathing/ digestion/ sexual arousal) The system works by itself and without conscious control.

Consists of two sub-systems

1. Sympathetic nervous system- FIGHT OR FLIGHT. Prepares body for action:-

•  Pupils Dilate
•  Accelerates heartbeat
• Heavy breathing
• Sweating
• Release of adrenaline

2. Parasympathetic nervous system- REST AND DIGEST. Supports normal body activity/ conserves energy.

• Pupils contract
• Slows heartbeat
• Stimulates digestive activity

Methodology of Biological approach

• Experiments are the main method…