Twin studies - Investigates the relation between genetics and environment on criminal behaviour by comparing concordance rates of criminal activity between monozygotic (identical) and dizygotic (non-identical) twins to help figure out the hereditary aspects of criminal conduct.
Twin Studies supports the contention that ‘heritable traits’ may increase risks of criminal behaviour.
Advantages of Twin Studies Theory
Natural experiments with a natural occurring variable that is measurable.
Supported by other studies, e.g. Christiensen - shows reliability.
Helped prevention of vulnerable disorders (looks at reoccurrence in genes).
Disadvantages of Twin Studies Theory
Early twin studies were inadequately controlled and lacked validity.
The small sample may not be representative of general population.
If twins are brough up on the same environment, criminality could just as easily be related to nurture as genetics.
