2.  Nature and nurture are both involved in controlling brain development, but scientists disagree about which one influences brain development the most.

3.  Scientists study the effects of different environments (nurture) on brain development of animals of the same species. Any differences in their brain development are more likely to be due to nurture than nature (if they’re the same species they’ll be genetically similar).  Hubel and Wiesel experiment on critical windows in visual pathway development. The cat visual system is very similar to humans. Studying how cats learn to see has helped doctors rehabilitate the vision of children with amblyopia (lazy eye) more effectively.

4. The brain of a newborn baby hasn’t really been affected by the environment. Scientists study the brains of newborn babies to see what functions they’re born with and how developed different parts of the brain are – what they’re born with is more likely to be due to nature than nurture.

5.  Study conducted by Christiansen in 1977 looked at 3586 pairs of twins in Denmark and found a 52% concordance rate for criminality in monozygotic twins and a 22% concordance for dizygotic twins.

7.  Children brought up in different cultures have different environmental influences e.g. social practices, beliefs, education, gender influences. Scientists can study the effects of different upbringing on brain development by comparing large groups of children who are the same age but from different cultures. Examples of experimental stimuli: A) Euro-American actor performs the classic American 'hang loose' gesture. B) Nicaraguan actor performs a typical Nicaraguan gesture 'I swear (promise)' and C) one of the control gestures modified from the ASL sign for 'berries'. D) Euro-American actor in the 'static' condition.