criminality and aggression is directly linked to genetics
regardless of the changed environment, children seemed biologically predisposed to criminality
Components
compared a group of adoptees with criminal mothers to a group of adoptees with non-criminal mothers
50% of adoptees with a criminal mother also had a criminal record by the time they turned 18
only 5% of adoptees who had a non-criminal mother had a criminal record b the time they were 18
Credibility
separates nature and nurture
classic research method
may not show that it is criminality being inherited
unknown sample size
deterministic
reductionist
Application
Kenneth Bianchi: serial killer who was given up for adoption by his 17 year old, prostitute mother
Refuting Evidence
no mention of the biological father
age of adoption may mean other life experiences influenced them
consider amount of contact with the biological parents
limited information on the biological parents
Supporting Evidence
Mednick et al1994: compared 14427 criminal records of adoptees to that of their biological and adoptive parents, found a correlation between the child and their biological parents