I haven't read the study, but I think there is an extremely high chance that this is showing confirmation bias. And i feel the video they show supports this int

I haven't read the study, but I think there is an extremely high chance that this is showing confirmation bias. And i feel the video they show supports this interpretation. I don't know monkeys so didn't know which ones had opposable thumbs but felt just from the hand movement that I understood when the researcher intended the monkey to follow the moving hand and when the researcher didn't, moving the hand more significantly when wanting the money to focus on it, and damping the movement when wanting it to focus on the still hand. If they didn't already do this, they should train some people to perform the trick that doesn't know the difference between the monkeys and don't know what the expected outcome is based on their current hypothesis.