Practise IB Psychology HL 2.1.6 by evaluating genetic and environmental contributions to behaviour and the evidence for each.
To what extent does genetic inheritance influence behaviour?
Refer to the paper 1 section B assessment criteria when awarding marks.
The command term "to what extent" requires candidates to consider the contribution of genetic inheritance on behaviour.
In responding, a candidate may choose a single behaviour, or they may choose a number of behaviours. The term "behaviour" may be considered broadly and could include schizophrenia, depression, obesity, intelligence, aggression and sexual orientation.
Candidates may use examples of inheritance from family, twin and adoption studies that look at concordance rates, or they may choose to look at studies of specific genes. Both approaches are equally acceptable. Candidates may also choose to address gene expression and gene x environment interactions.
It may be appropriate and useful for candidates to address sociocultural and/or cognitive factors in order to address the command term "to what extent". It would also be appropriate to look at the strengths and limitations of genetic evidence.
Examples of relevant studies include, but are not limited to:
- Heston's (1966), Gottesman's (1991) and Kety et al.'s (1975) studies examining the role of genetic inheritance in schizophrenia
- Kendler et al. (2006), Caspi et al. (2003) and Nurnberger and Gershon (1982) on the role of genetic inheritance in depression
- Garn et al. (1981) and Stunkard et al. (1990) on the role of genetic inheritance in obesity
- Bouchard et al. (1990), Scarr and Weinberg (1977), and Plomin and Petrill (1977) on the role of genetic inheritance in intelligence.
If a candidate makes reference to research from evolutionary psychology, the focus of the response must be on how genetic inheritance may influence the behaviour.