https://www.livescience.com/animals/chimps-think-about-thinking-in-order-to-weigh-evidence-and-plan-their-actions-new-research-suggests
"
In the final test, the researchers again added extra evidence for the apes to consider after they had made their first choice. This time, the new evidence undermined the first piece of evidence; for example, by showing the chimps a pebble inside one of the boxes that could have made the rattling sound they had previously heard. The apes consistently responded to this contradictory evidence by changing their mind..."
