Biological Explanations: Studies
Psychology: AQA A Level, topic 13.1.10
Stunkard et al (1986) - Adoption Studies and Obesity
Stunkard et al (1986) investigated genetic factors in obesity through adoption studies.
Procedure
- Case study.
- 540 Danish adoptees were classified into four groups: thin, median weight, overweight and obese.
- These were then compared with their biological and adoptive families.
Results & conclusions
- Results
- There was a strong relationship between weight of biological parents and adoptees and no relationship between adoptive parents and adoptees.
- Conclusion
- This shows a strong genetic element in obesity and that environment may be less important.
Evaluation
- Strengths
- Large sample.
- In depth and detailed.
- Limitations
- Cannot generalise from case studies.
- Individual differences.
- Genes are not destiny, might just increase risk of obesity.
Hetherington and Ranson (1940)
Hetherington and Ranson (1940) investigated the effects of ventro-medial hypothalamus (VMH) lesioning in rats.
Procedure
- Procedure
- Laboratory experiment.
- Rats had the ventro-medial hypothalamus in their brains destroyed.
- Results
- The rats with lesions in the VMH had much higher food and water intake levels than rats without lesions and became very obese.
- Conclusion
- Demonstrates the importance of the VMH in regulating hunger and thirst.
Evaluation
- Strengths
- Controlled, reliable experiment.
- Practical applications.
- Limitations
- Cannot generalise from animals to humans.
- Ethics.
Test yourself on Biological Explanations: Studies
What was Stunkard et al's (1986) research method?
What were the four groups in Stunkard et al's (1986) experiment?
What was Hetherington and Ranson's (1940) experiment?