Biological Etiology | Psychology

Genetic Inheritance

Genetic researchers claim that predisposition to behaviours are genetic, and behaviour are triggered when expressed through an interaction between environmental stressful events.

Epigenetics

When genes are turned on/off due to environmental stress.

Twin Studies

Mono- (MZ) and dizygotic (DZ) twins are compared in studies, the former twins sharing 100% DNA while the latter share 50%. If MZ twins have a higher concordance rate, behaviours have a genetic component.

Strengths of Twin Studies

+ Results have been replicated —> High Reliability
+ First step into genetic research.

Limitations of Twin Studies

- Low Population Validity
- Ecological Environmental Fallacy

Family Studies

Investigates the frequency of a behaviour running in families across several generations and observe if closer relatives are more likely to share a behaviour.

Strengths of Family Studies

+ First step into candidate gene research.
+ More representative than twin studies.

Limitations of Family Studies

- Obtained retrospective data of past generations —> Low reliability