The Biological Approach

Basic Assumptions of the Biological Approach 

• Bevaviour and thought processes have an innate, biological basis
• The mind and the brain are the same
• Human genes have evolved to adapt behaviour to the environment
• Human characteristics, for example intelligence are due to our gentic make-up.

(a) Understand what is meant by Biological Psychology

Biology is defined as the study of life.

A biological perspective can be relevant to the field of psychology in three ways:

• Physiology - investigating how the brain, the nervous system and hormones operate and how the changes of structure and function of organs can effect our behaviour.
• Investigation of heritability - understanding genes and how it might affect our behaviour. For example, is intelligence inherited?
• Comparative method - different speices of animals are studied and compared to humans, this way we can learn and understand more about human behaviour. 

(b) Explain the influence of genes on behaviour

The nucleus of every cell contains 46 chromosomes 

Chromosomes are made up of DNA 

The DNA carries genes 

Research on the genetic influence of genes has often been conducted on animals such as rats and mice. This is beccause they have a shorter gestation period. 

Psychologists are able to manipulate certain genes in order to measure the effects on behaviour.  

Genetic mapping, genetic engineering and selective breeding are programmes that have contributed to our understanding of the genetic basis of behaviour.

Study to support influence of genes on behaviour: Bock and Goode (1996)

• Bock and Goode found that when mice were reared alone, they showed a strong tendency to attack other male mice when first exposed to other animals 
• These mice were not taught to be aggresive, they exhibited the behaviour from their parents 
• This research implies a natural, or genetic tendency in relation to biological aggression 

(c)  Suggest how evolutionary theory can be used to explain human and non-human behaviour 

Aggression is one of a number of primitive factors that both human and non-human species display.

Darwin proposed the theory that all living things have evolved over time from common ancestors, through the process of natural selection. The theory shows how strongest genes survive and are passed on to the next generation whilst maladaptive genes die out.

Sexual selection in animals and the rooting reflex in humans are both examples of evolutinary behaviour.

(d) Evaluate the biological approach 

Strenghts 

• The biological approach uses scientific, experimental proccedures in its investgations
• It provides strong arguments for the nature side of the natrue-nurture debate 
• The biological approach has many uses applications, for example, drugs that alleviate disorders such as bipolar depression 

Limitations 

• The biological approach is reductionist. It explains all thoughts and behaviours in terms of actions of nerves or chemicals.
• The approach is over-simplistic as it fails to fully appreciate that behaviour can be effected by environmental factors 
• The approach raises ethical issues, for example, gentic mapping. People question whether it is right to artificially manipulate our genetic make-up