Describe the sample used in the study by Hassett et al. (monkey toy preferences).

Mark scheme

Marking points from the official mark scheme (Feb/Mar 2025). The mark or mark type is shown in brackets.

1. [1] Rhesus monkeys.
2. [1] Troop of 135 individuals.
3. [1] Lived together for more than 25 years.
4. [1] Lived at Yerkes Center.
5. [1] Matriline social structure/same natal group.
6. [1] 14 not used due to hormonal treatment.
7. [1] Age range 3 months to over 13 years.
8. [1] 61 females/21 males/more females than males used as potential participants/82 potential participants.
9. [1] 23 females/11 males/34 monkeys used in data analysis.
10. [1] 39 infants not used (as interactions not coded).
11. [1] 53 monkeys were excluded in total.
12. [4] Similarity: A well-explained similarity between Hassett et al. and another biological study, using both studies as examples (e.g., adherence to ethical guidelines, scientific approach, quantitative data).
13. [4] Difference: A well-explained difference between Hassett et al. and another biological study, using both studies as examples (e.g., experimental design, type of data, brain measurement).
14. For similarity, both Hassett et al. and Hölzel et al. conformed to relevant ethical body guidelines (e.g., NIH Guidance for Hassett, hospital/medical school for Hölzel).
15. For difference, Hassett et al. used observational methods to collect quantitative data on toy preferences, while Dement and Kleitman used a lab experiment to collect physiological data (EEG) and self-reports on dream content.