Biological Approach

What is the biological approach?

Each persons behaviour is determined by a unique genetic code, which arises through genetic variation. Each gene has alleles that make a person’s genotype. Each gene, along with the environment, shapes a persons phenotype.

What is genetic variation?

The genetic difference between individuals - what contributes to a species adaption to its environment.

What is DNA?

Deoxyribonucleic acid - long strips of genetic material made up of many genes.

What is a genotype?

The genetic material from the parents.

What is a phenotype?

How genes are expressed as characteristics - determined by our genotype and influences from the environment.

How are genes linked to behaviour?

Genes have been found to be associated with temperament and psychological disorders e.g. depression or schizophrenia.

What did Heston (1966) find in regards to genes affecting behaviour?

A study into adoptees development of schizophrenia found that 36.8% of adoptees at high genetic risks of schizophrenia brought up in disturbed environments were likely to develop the disorder compared to 5.8% of adoptees at high genetic risk brought up in undisturbed environments.

What is Darwin’s theory of evolution by natural selection?

Organisms that are better suited for their environment will survive and reproduce while others die out.

What is the evolutionary psychological approach?

The idea that the outcome of a behaviour in a particular situation can be predicted based on evolutionary theory - only if the behaviour is genetically caused.

What behaviour can evolution make predictions for?

Memory

Mate choice

Kin relationship

Friendship / co-operation

Parenting

Social organisation

Status

What is a limitation of evolutionary psychology?

The traits that we possess now evolved under environmental and social conditions for back in history that we have a poor understanding of. So we cannot make predictions about what is adaptive for behaviour because they don’t need to be adaptive under current conditions.

How did Gottesman study the effect of genetics on behaviour?

A meta-analysis of twin studies - investigating the concordance rate of schizophrenia in twins.

What did Gottesman find?

There was a 48% concordance rate in monozygotic twins and a 17% concordance rate in dizygotic twins.

What are monozygotic twins?

Share 100% of the same genes.

What are dizygotic twins?

Share about 50% of the same genes.

What does Gottesman’s study show about the development of schizophrenia?

It suggest the onset of schizophrenia does have a large genetic component but as the concordance rate is not 100%, when MZ twins shared 100% of the same genes, there must be other factors at play.

What is the case study of Phineas Gage?

Suffered an accident age 25 where an iron bar went through his eye socket and out the other side of his head. He survived but his personality change.

What does Phineas Gage show about localisation in the brain?

Localisation is where each part of the brain has a function. As Phineas’ frontal lobe was damaged, he had difficulty with decision-making and impulse control.

What types of brain scan techniques are used?

PET scans - Positron Emission Tomography

ERPs - Event Related Potentials

MEGs - Magnetoencephalograms

EEGs - Electroencephalograms

fMRI scans - functional Magnetic Resonance Imaging

What did Maguire et al (2000) find?

Used MRI scans on taxi drivers and a control group. Found that the posterior hippocampi of taxi drivers was significantly larger and that hippocampal volume correlated with the years spent taxi driving - shows the brains plasticity, how it changes to suit the demands placed on it.