BLOA - to what extent does genetic inheritance influence behaviour?

Question 1

aggression

Answer 1

• behaviour causing pain/harm in others
• labeled as aggression only when the behaviour is intended to cause harm

a doctor giving an injection causes pain but the act isn’t aggressive as his intention isn’t to harm the individual

Question 2

genetic inheritance and aggression

Answer 2

• animal studies have shown clear link between aggression and genetic inheritance

Cited studies:

• Bock and Goode (1996)
• Suomi and Lesch (2002)

Question 3

Bock and Goode (1996) - Aim

Answer 3

investigate effects of serotonin on aggression

Question 4

Bock and Goode (1996) - Process

Answer 4

2 conditions:

• serotonin inhibited
• control
• low serotonin levels are correlated with aggression
• mice in the first condition had their serotonin receptor sites genetically manipulated via breeding
• by having the gene responsible for producing serotonin receptor proteins removed
• aggression was measured by the amount of bites/attacks

Question 5

Bock and Goode (1996) - Findings

Answer 5

serotonin-inhibited mice reared without aggressive role models still showed aggressive behaviour

Question 6

Bock and Goode (1996) - Conclusion

Answer 6

aggression can be correlated with genetics

Question 7

Bock and Goode (1996) - Evaluation

Answer 7

• tightly controlled
• quantifiable and clear IV/DV
• ethical guidelines for treatment of animals followed
• as animals were bred for experimental purposes

Question 8

Suomi and Lesch (2002)

Answer 8

• identified a gene that affects effectiveness of processing serotonin
• cerebral spinal fluid of 132 juvenile rhesus monkeys was collected
• analysed for serotonin metabolite traces (high metabolite level = high efficiency of serotonin processing)
• monkeys that had low metabolite levels were more aggressive

Question 9

extent of influence of inheritance on behaviour

Answer 9

• animal studies have shown clear link between aggression and genetic inheritance
• but it’s reductionist and simplistic to assume genes are solely responsible for complex behaviour
• aggression is a complex human behaviour
• unlikely to be the result of one genetic trait
• more likely the result of a combination of environmental and genetic factors
• factors in the environment (e.g. parenting) must always be considered

cited studies:

• Suomi (2002)
• Caspie and Moffitt (2012)

Question 10

Suomi (2002)

Answer 10

• noted that bullies came from stern mothers while neurotics came from shy mothers
• he took neurotic babies (babies that had nervous dispositions) from neurotic mothers
• gave them to nurturing mothers (supermoms)
• when raised by supermoms, the babies turned out very close to normal
• shows that environment has a clear impact on behaviour

Question 11

Caspi and Moffitt (2012)

Answer 11

• conducted 26 year longitudinal study
• involved 1036 children born in 1972 NZ
• children inheriting a short version of the gene MAOA were more likely to exhibit aggression
• but this was only in cases where the children experienced an abusive upbringing
• carriers of MAOA who experienced good parenting were usually normal

Question 12

evaluation of gene research (strengths vs weaknesses)

Answer 12

Strengths:
- helps us determine the effect of particular genes on behaviour

Weaknesses:

• genes interact with the environment in complex ways
• knowledge about genes is still limited

Question 13

evaluation of animal studies (strengths vs weaknesses)

Answer 13

Strengths:

• animal studies allow high levels of manipulation that would not be allowed on humans
• findings help us understand biological mechanisms

Weaknesses:
- caution should be used when generalizing findings
of animal studies to humans

Question 14

what to write when asked: “to what extent does genetic inheritance influence behaviour?”

Answer 14

• define aggression
• describe + explain the link between genes and aggression – Bock and Goode (1996), Suomi and Lesch (2002)
• investigate alternate factor (effect of environment on behaviour) – Suomi (2002), Caspie and Moffitt (2012)
• evaluate studies mentioned
• discuss the ecological validity of genetic research
• weigh benefits and limitations of using genetic research to understand behaviour
• when stating opinions, mention empirical evidence
• form a clear conclusion by discussing the relative importance of genes vs environment on behaviour