Spinelli Et Al Study (bio)

Question 1

Spinelli Et Al Study (bio)

Aim

Answer 1

To analyse the relationship between serotonin transporter gene, life experience and exposure to stress (separation experiment) in rhesus macaques (monkeys).

Question 2

Spinelli Et Al Study (bio)

Procedure

Answer 2

• Monkeys were split into two groups:
  
  • Peer-reared (PR): Housed in an incubator for the first 14 days of life then placed alone in a nursery cage with a surrogate. After approx one month monkeys were put into a cage with three other monkeys. (this is meant to be a stressful upbringing)
  • Mother-reared (MR): Raised with their mother in a social group with 8 - 12 adults females (about half of whom had same-aged infants) and two adult males (This is meant to be typical upbringing)
• Separation producers after 6 - 7 months (procedure lasted four-days):
  
  • PR: Put int individual compartments of the cage (couldn’t see but could hear peers)
  • MR: Mother was removed from the social group
• Day 1 is the “acute phase”, Day 2-4 is “chronic phase”
• Behavioural observations were made and recorded based on genes

Question 3

Spinelli Et Al Study (bio)

Findings

Answer 3

• PR monkeys showed more despair than MR monkeys
• PR l/s monkeys showed more pathological behaviours (ex. Any repetitive, patterned, and rhythmic locomotive movement) than PR l/l monkeys
• PR l/l monkeys showed more despair the PR l/s monkeys
• Researchers hypothesise that behaviours associated with despair are actually coping mechanisms
• Carriers of s allele were more likely to develop pathological behaviours
• Findings support the influence of genes on behaviour as groups behaved differently in reaction to separation

Question 4

Spinelli Et Al Study (bio)

Limitations

Answer 4

• External Validity
  
  • Does not directly support the findings of the human study (Caspi Et Al)
  • Gene is not identical to the human gene
• Difficult to draw conclusions for animal behaviour (ex. Despair = depression or coping mechanism?)
• s/s monkey not included in the study

Question 5

Spinelli Et Al Study (bio)

Ethical Considerations

Answer 5

• Special justification required for:
  
  • Peer-reared upbringing
  • Separation
  • Euthanization would not be required at the end of the experiment however monkeys with “peer-reared upbringing” would only be appropriate subjects for similar experiments

Question 6

Spinelli Et Al Study (bio)

Research Method

Answer 6

Experiment