Jan Engelmann
janengelmann.bsky.social
Jan Engelmann
@janengelmann.bsky.social
Associate Professor of Psychology at UC Berkeley and Director of the Social Origins Lab: https://socialoriginslab.com/
We also showed that chimpanzees respond appropriately to so-called “second-order evidence”—that is, evidence about evidence.

This indicates that chimpanzees explicitly represent what has been called the *evidential relation*: the causal connection between evidence and hypothesis. (6/8)
October 30, 2025 at 6:47 PM
Our study also suggests that chimpanzees *explicitly* represented the evidence for their beliefs.

When we showed them evidence, and then showed them that *same* piece of evidence again later, they disregarded it. When they instead saw a *new* piece of evidence, they changed their minds. (5/8)
October 30, 2025 at 6:47 PM
Chimpanzees responded to the counterevidence in line with the rational predictions of a mathematical model of rational belief revision.

That is: they revised their prior belief when the counterevidence was stronger than the initial evidence, but maintained their belief otherwise (4/8)
October 30, 2025 at 6:47 PM
Chimpanzees participated in a foraging task. We first gave them evidence that food was in one location, and let them make a first choice. Then we presented them with *counterevidence*: evidence for the other location. (3/8)
October 30, 2025 at 6:47 PM
Congratulations!!! Let's celebrate together in Berlin :)
July 20, 2025 at 8:49 AM
Reposted by Jan Engelmann
Before, they are altercentric and remember better things that are relevant for others; afterwards, they shift towards egocentrism, remembering better things that are relevant for themselves - as we also do as adults.
July 9, 2025 at 3:59 PM