How have African gray parrots shown deductive reasoning in experiments?

Research has demonstrated that African gray parrots possess significant cognitive abilities, including the capacity for deductive reasoning. In experimental settings, these birds have shown they can use deductive reasoning to correctly choose between pairs of boxes—one containing food and the other empty—when the containers are shaken to provide auditory cues. Furthermore, studies have observed that pairs of African gray parrots are capable of working together to successfully obtain a food reward.1

These findings contribute to the understanding that the intelligence of the African gray parrot ranks among the highest of nonhuman animals, with some researchers comparing their reasoning abilities to those of a three- or four-year-old human child.1