In the study by Yamamoto et al. (chimpanzee helping), one variable being measured was the object offered by a chimpanzee.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2020). The mark or mark type is shown in brackets.

1. [1] (a) 1 mark for feature of object offer x2
2. [1] (a) Helper held out an object (tool) to the recipient = 1
3. [1] (a) Only the first object offered counted = 1
4. [1] (a) Correct or incorrect tool offer / tool or non-tool / stick, straw or hose, chain, rope, brush, belt = 1
5. [0] (a) 'Correct tool' / stick or straw only = 0 'Incorrect tool' / hose, chain, rope, brush, belt only = 0
6. [1] (b) 1 mark for reason for ecologically valid or not (no mark for just 'yes' or 'no');
7. [1] (b) 1 mark for detail or for second reason (if two reasons, can be one 'yes' and one 'no');
8. [] (b) For 2 marks the answer must have a link;
9. [1] (b) Yes, because chimpanzees are social animals so do communicate = 1 reason (+ link)
10. [1] (b) So they would communicate about food to help each other = 1 detail
11. [1] (b) Yes because chimpanzees are intelligent animals who use tools = 1 reason (+ link)
12. [1] (b) So they could use each other's tools in the wild = 1 detail (also + link)
13. [1] (b) No because chimpanzees wouldn't normally use tools (i.e. straws/hose/ chain/rope/brush/belt) = 1 reason (+ link)
14. [1] (b) They would use stones/natural objects = 1 link
15. [1] (b) Yes, because helping is a normal behaviour = 1 reason (no link)
16. [1] (b) No, because the task wouldn't happen in the wild / no because it is in a lab (not in the wild) = 1 reason (no link)