The Genetic Explanation Of Aggression Flashcards
What is a genotype?
An Individuals unique set of genes that code for their development eg. eyecolour
What is a phenotype?
An observable result of the interaction between the genotype and the environment eg. hair dye
Why can aggression increase due to genes?
A defective gene is inherited leading directly to aggression
Eg. Low activity if the MAOA gene leads to the imbalance of neurotransmitters increasing aggression
This is studied using genetic testing, family history or twin studies
Or a defective gene can be inherited however aggression develops after DNA has interacted with the environment
Eg. Low activity of MAOA gene and experience of childhood trauma
What is Concordance?
The probability that a pair of individuals will both have certain characteristics, given one of the pair has the characteristic.
What are Monozygotic twins?
Identical twins that share 100% same DNA
What are Dizygotic twins?
Non-identical twins share 50% same DNA
What is the assumption of twin studies?
Concordance
What is the assumption of adoption studies?
If behaviour of the adopted child is similar to biological parents- genes play a roles. However, if behaviour of the adopted child is similar to the adopted parents the behaviour must stem from the environment
How are genetic explanations of aggression tested?
Genetic testing, family history and twin studies are used to study how an inherited defective gene leads directly to aggression.
Investigations of trauma, genetic, twin and adoption studies are used to study how an inherited defective gene interacts with the environment to develop aggression
What is the problem of genetic testing?
Difficult to separate genes and the environment
Why are twin studies used to investigate genetic explanations of behaviour?
Similar behaviours observed in identical twins (100% DNA shared) assume it is due to genetics, however similar behaviours seen in non-identical twins (50% DNA shared) assume that the cause is due to either genetics of the environment.
Why is it difficult to determine whether a behaviour is due to genetics or the environment?
There is the problem that the environment begins to influence our genes from the womb, even identical twins will have different environmental exposures- this may range from parenting, friendship groups or what they learn.
Describe the genetic explanation of aggression (4 marks)
The genetic explanation suggests that individuals may be predisposed to aggressive tendencies and behaviour due to their genes. Individuals may have one or more genes that can increase the risk of aggression, such as the defective MAOA gene. However, genetic explanation does acknowledge the influence of the environment as an individuals personality may differ from their coded characteristics because of the interaction between an individual’s genes and environmental factors. Psychologists test the influence of genetics and environmental factors on behaviour using twin and adoption studies.
