Quiz 1 - Chapter 2 Flashcards
What is Cesare Lombroso considered as?
Father of Criminology
Atavism
Criminals are “evolutionary throwbacks”; as indicated by physical features
Atavistic characteristics
E.g., asymmetric face, long arms, large jaw, sloping forehead
Modern views on atavism
No meaningful statistical comparisons between people who do and do not commit crimes
Theories discredited
What is Galton considered?
Father of eugenics
Eugenics
Any practice (e.g., forced sterilization, genocide) aimed at “improving” the human species
Two broad methods of eugenics
Discourages reproduction among those with “undesirable traits”
Encourages reproduction among those with “desirable traits”
Canadian example of eugenics
1930s-1970s: AB and BC had legislation allowing sterilization based on mental and physical “health issues”
6 criteria for a good theory
Parsimonious
Causal mechanisms, mediators, moderators
Testable and falsifiable
Empirical data
Interdisciplinary compatibility
Respects gender, ethnicity, culture
Aim of behavioural genetics
Can help separate genetic and environmental influences to some degree
How much of DNA is shared by all humans? What varies?
All humans share 99.9% DNA
0.1% varies
Monozygotic twins
Genetically identical (share ~100% genes)
Dizygotic twins
Same genetic similarity as typical siblings (50%)
Concordance rate
Likelihood both twins engage in same behaviour
% at which both twins have been justic-involved
What is the purpose of comparing concordance rates between identical and fraternal twins?
How?
Helps to separate effects of genetics vs. environment
If concordance rate is higher among individual twins, then we assume a genetic influence
What is the concordance rate of eye colour?
Entirely genetic
50% for fraternal vs. 100% for identical
What is the concordance rate of criminal offending? What does this tell us?
61% for fraternal vs. 81% for identical
Genetics are linked to crime, but certainly not the whole picture
What is another indication of twin studies?
They also indicate degree of environmental (not just genetic) influence
What do twin studies show about shared environmental factors?
Aspects of environment shared by family members (e.g., exposure to abuse/neglect, living in poverty); 40%
What do twin studies show about nonshared environmental factors?
Aspects of environment not shared by all family members (e.g., peer groups); 19%
What is a criticism of twin studies?
May overestimate genetic contributions
E.g., MZ twins likely have more similar environments than DZ twins
What are adoption studies better at than twin studies?
Adoption studies can better control for environment
Parent-offspring studies
Concordance rates between adoptive parents and adopted children are compared to concordance rates between biological parents and adopted children
Sibling-offspring studies
Concordance between adoptive siblings vs. biological siblings
Mednick et al. (1984) explanation
Study on 14,427 non-familial adoptions in Denmark
Mednick et al. (1984) results
If no parents had criminal record: 13.5% of sons had criminal record
If adopted parent had criminal record, but not the biological parent: 14.7%
If biological parent had criminal record, but not the adopted parent: 20%
If both sets of parents had criminal record: 24.5%
Findings of meta-analysis by Besemer et al., 2017
Found that the odds of a person committing a crime doubles if one of their (genetic) parents commits a crime (due to genes and environment)
