A cognitive fallacy in a fish? Glass catfish, like humans, make sub-optimal choices in the Monty Hall dilemma

Exploring cognitive fallacies is a key pursuit for neuroscientists as they offer a unique window into the foundations of how we think and make decisions. The Monty Hall dilemma (MHD) is a probability puzzle in which a person is offered a choice among three doors, behind one of which is a prize. After the person selects one door, the remaining door without the prize is revealed. The person is now given the option to either keep their original choice or switch to the other door. Most people stick with the initial choice, even though switching would offer a higher chance of winning. Here, we observed that a distantly related species, such as fish, shows a human-like behavior in the MHD, as they consistently maintained their first option. Our study suggests that the mechanisms behind misjudging two-stage decision-making involving conditioned probabilities may also be shared by smaller, non-cortical brains.