HUGE thanks to our incredible team: @janengelmann.bsky.social and the @socialoriginslab.bsky.social, @estherherrmann.bsky.social, @wdt.bsky.social, Josep Call, Snow Zhang, Dr. Joshua Rukundo and the Ngamba Island Chimpanzee Sanctuary, and most of all, thanks to the brilliant chimpanzees!!

“It is a profound gift to know that when a chimpanzee stares into a person’s eyes, they too could be reflecting on their beliefs about humans.” - Brian Hare (photo by Innocent Ampeire) www.science.org/doi/10.1126/...

Across experiments, our computational modeling analyses demonstrated that the best explanation for the chimps’ behavior was rational reasoning.

My favorite result: chimps metacognitively re-evaluated old evidence. We showed them food in the box, then we showed them that there was a sticker that looked like food in the box. Astonishingly, chimps re-evaluated their previous construal of the evidence, revising their belief away from that box!

In our study, chimps had to guess where food was hidden. They got strong evidence for one box and weak evidence for the other. Consistent with rationality, the chimps revised their choice more often when weak evidence came first, overwhelmingly choosing the option supported by stronger evidence!

i don't believe these because you're not willing to write 900 pages of notes on a 300 page book, which is critical for an accurate michael impression