Twin Studies Flashcards
Why do researchers study twins?
There is evidence that suggests that criminal behaviour runs in families and transmitted genetically.
Twins are also genetically similar, therefore the concordance rate can be studied.
What is the scientific term for identical twins?
Monozygotic (MZ).
What is the scientific term for non-identical twins?
Dizygotic (DZ).
What is a concordance rate?
The comparison of two characteristics and how similar they are.
Who conducted research on twins?
Lange (1930).
How many twins did Lange investigate?
13 identical (MZ) twins and 17 non-identical (DZ) twins. In addition, one twin of the pairs had served time in prison.
What did Lange find in his investigation?
Lange found a 59% concordance rate in MZ twins and a 12% concordance rate in DZ twins.
What did Lange conclude?
Lange concluded that genetic factors must play a predominant part in offending behaviour.
What is one strength of twin studies?
They are a good way of studying genetic links in criminality because if MZ twins are more likely to both become criminals than DZ then this supports the idea of inheritance and genetics involvement.
What is a problem behind the concordance rate?
The concordance rate is never 100%, therefore the environment must play a role in criminality.
What is one weakness of twin studies?
MZ twins are more likely to share the same environment; because identical twins look the same, they are more likely to be treated more similarly than DZ twins which could explain the higher concordance rate in MZ twins.
Who conducted research in 1930?
Lange.
What does 59% refer to?
The concordance rate of identical twins.
What does 12% refer to?
The concordance rate of non-identical twins.
What does 13 refer to?
The number of identical twins Lange studied.
