Apes’s visual illusions

Audrey E. Parrish,   Sarah F. Brosnan, and Michael J. Beran published a comparative investigation of the Delboeuf illusion in humans and a couple of monkeys species.   Theis research bring evidence of relative size perception illusion across those species.

Parrish and Beran’s previous research on how both humans and chimpanzees misperceive food amounts based on plate size target a similar topic.

Interestingly, in the case of the chimpanzees studies it was possible to observe not only a visual illusion.  Feeding and consumption behavior changed accordingly as well.  It is not out of the ballpark to characterize greed and accumulation in excess resulting in illusory perception.  Perhaps understanding better the foundation of such illusions help humans distancing our behaviour in a more conscious fashion.