An illusion involving a hidden thumb confounds capuchin and squirrel monkeys for the same reason it does humans -- it misdirects expected outcomes of actions they can carry out. However, marmosets ...

A team of researchers performed magic tricks for several species of monkey, and they found that the animals’ gullibility may depend on the structure of their hands. Specifically, the team found that ...

A Humboldt's squirrel monkey is fooled by the "French Drop" magic trick. Credit: E. Garcia-Pelegrin et al., 2023 The key to a successful sleight-of-hand magic trick is how well a magician manipulates ...

Monkeys with hands that resemble ours fall for a sleight-of-hand magic trick, but those without opposable thumbs aren’t fooled. These differences illustrate how primates’ expectations of the actions ...

Psychologists used a sleight-of-hand trick called the French drop, in which an object appears to vanish when a spectator assumes it is taken from one hand by the hidden thumb of the other hand. The ...