AC2.1 describe biological theories of criminality

what are the 2 biological theories?

genetic theories and physiological theories.

what is 1 example of a genetic theory?

Jacob XYY study

what is an XYY man?

XY is the chromosome that is in men,however sometimes there might be an extra Y chromosome which makes XYY men.

what does an XYY man usually look like?

very tall and well built, and of low intelligence.

what did Jacob et al say about XYY men?

he said that men with the XYY syndrome were more aggressive

than normal XY men.

why are XYY men overepresented in prison?

there are 15 XYY men per 1000 in prisons and 1 XYY man per 1000 in the general population.

what is an example of a criminal with XYY syndrome?

serial killer John Wayne Gacy who raped, tortured and murdered at least 33 teenage boys and young men between 1972 and 1978 in Cook County, Illinois.

what is another example of genetic theories?

twin studies

what is the theory of twin studies about?

Identical twins can be tested as a way to test if one member has ‘criminal genes’, it is likely that their blood relatives will have them too.Identical or monozygotic twins share the same genes,so if one twin is a criminal it is likely the other twin will be too.

what are 2 limitations of twin studies?

small sample in twin studies may not represent the general population

If twins are brought up in the same environment criminality couldn’t be due to their environment not genetics.

what is an example of a physiological theory?

Sheldon’s somatotypes theory.

what was sheldons theory?

that certain body types were linked to criminal behaviour.

what are 3 characteristics of endomorphs?

rounded, soft without muscles

what are the personality traits of endomorphs?

sociable, outgoing and comfortable

what are 3 characteristics of ectomorphs?

thin and fragile, lacking both fat and muscle.

what are 3 personality traits of ectomorphs?

self-conscious,introverted and thoughtful.

what are 3 characteristics of mesomorphs?

muscular and hard bodied, with very little fat

what are 2 personality traits of mesomorphs?

adventurous and sensation-seeking

which of the somatotypes are most likely to commit crime and why?

mesomorphs are the somatotypes most likely to engage in crime because they are more likely to be attracted to risk-taking and also their imposing physique can help them to commit crime.

what are 2 limitations of sheldons study?

-peoples body type can change throughout their life.

-endomorphs and ectomorphs still commit crime.

what is an example of a physiological theory?

brain abnormalities (raine et al 194 NGRI)