The Biological Approach

Biological approach

A perspective that emphasises the importance of physical processes in the body like genetic inheritance and neural function

Biological structure

Any physical part or system in the body that helps support, sustain or perform any of the vital functions in our bodies, e.g. brain, heart, legs, skin, nerves and blood

Cognitive neuroscience

The scientific study of those biological structures that underpin cognitive processes

Neurochemistry

Concerned with the chemicals that assist in the activity of transmission throughout the nervous system

Evolution

The changes in inherited characteristics in a biological population over successive generations

Genetic

The study of genes, the core elements of chromosomes and consist of DNA which codes the physical and psychological features of an organism.

Genes are transmitted from parents to offspring

Genotype

The particular set of genes that a person possesses

Phenotype

The characteristics of an individual determined by both genes and the environment

Assumptions

Suggests that everything psychological is at first biological. To understand human behaviour we must study biological structures and processes.

All thoughts, feelings and behaviours have a physical basis

Genetic basis of behaviour

Mainly uses twin studies to see if certain characteristics have a genetic basis. Achieved by analysing concordance rates.

If a characteristic is genetic we would expect all identical (MZ) twins to be the same as they share 100% of the same genes. Non-identical (DZ) twins share about 50% of the same genes so we would expect lower concordance.

MZ and DZ twin pairs are assumed to share the same environment. Biological siblings also share 50% of the same genes but are likely to have differences in terms of the environment.

Despite having the same basic genes, MZ twins may express their genes physically or behaviourally different. This suggests that human behaviour depends on an interaction between inherited factors and the environment.

Evolution is proven as a fact through Charles Darwin’s theory of natural selection: any genetically-determined behaviour that enhances an individual’s survival will continue in future generations. Natural selection occurs because some traits give the possessor advantages. They are more likely to survive, reproduce and pass on these traits.

Lisofsky neuroscience meta-analysis

Used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scans to locate a network of brain regions which are activated when we lie, including prefrontal cortex and anterior cingulate cortex (ACC). The findings can be applied in criminal trials to help determine whether an accused person tells the truth by scanning their brains.

S Real-world application

Research into effects of neurotransmitters has revealed that there may be a neurochemical imbalance which contributes to depression

This has led to development of drug treatments that correct the imbalance and minimise symptoms.

Positive contribution to understanding and dealing with human behaviour

W Not objective

Bennett

Involved a dead salmon which was in an fMRI scanner. When the researchers started looking at the voxels in various scans of the fish, it appeared the fish’s brain was active as the voxels were changing.

They weren’t changing but false positives make it look like they were

Suggests that biological methods may lack validity.

W Determinist

It sees human behaviour as governed by internal, genetic causes over which we have no control. However, we have already seen the way in which an individual’s genotype is expressed is heavily influenced by the environment. Not all MZ twins look or think the same.

A purely genetic argument becomes problematic when we consider crime. Could a violent criminal excuse their actions by claiming their behaviour was caused by a “crime gene”

Suggests that the biological view is too simplistic and ignores mediating effects.

W Reductionist

Isolates genes as the main cause of a behaviour may ignore other factors like cognitive, social, developmental, cultural. Doesn’t take these factors into account.