Object Permanence

Object permanence is one of the most studied abilities in animal cognition. In the early twentieth century, researchers investigated memory by hiding a food reward in one of several opaque containers and allowing the animal to retrieve it after a delay (e.g., Tinklepaugh 1928). This research on delayed reactions tacitly involved object permanence, which was not explicitly considered a separate cognitive capacity until the influential studies of Piaget (1954). He found that children develop object permanence in stages throughout early childhood. Behavioral biologists and comparative psychologists later used the Piagetian framework to document the cognitive development of various species. They discovered that not all species reach all six stages of object permanence as humans do while acknowledging that the Piagetian tasks are not suitable for many species and that numerous other factors affect performance. The debate on optimal methods continues. Recent research tries to disentangle these confounds and test animals in multiple carefully controlled conditions, with the overarching aim to describe why some species perform better than others in the light of their respective natural histories.