Genes

Question 1

Psychologists complete research on twins to study

Answer 1

the role of genes and behaviour in order to determine how much human behaviour is influenced by genetics and how much by our environment.

Question 2

Monozygotic twins (MZ)

Answer 2

are identical and therefore share a 100% of their DNA. Thus if a behaviour is entirely determined by genes then we would expect both people in the twin pairing to exhibit the behaviour; the concordance rate should be 100%.

Question 3

dizygotic twins (DZ)

Answer 3

no more alike than siblings, sharing approximately 50% of their DNA, thus we would expect a lower concordance rate than that seen for monozygotic twins but a higher concordance rate than the prevalence rate in the general population due to them sharing a similar environment.

Question 4

Concordance rate

Answer 4

Psychologists can compare the concordance rates for monozygotic and dizygotic twins to help them determine whether a behaviour is caused by biological factors or environmental. One behaviour that psychologists study is sexual orientation.

Question 5

The research completed by Baili suggests

Answer 5

that sexual orientation is a least in part caused by genetics. Although the concordance rate was not 100% it was significantly higher than for dizygotic twins and for non related brothers. This would suggests that genetics can predispose us to certain behaviours. Whether this is depression, criminality or indeed homosexuality.