| Sample size | Experiment type | Source | Source title |
|---|---|---|---|
| 7 | experimental | Bohn et al. 2017 | Information seeking about tool properties in great apes |
| 8 | experimental | Call 2010 | Do apes know that they could be wrong? |
| 12 | experimental | Call and Carpenter 2001 | Do apes and children know what they have seen? |