A-not-B error

The A-not-B reaching error has been shown to exist in most non-human species tested so far. There are a few exceptions: apes (apart from orang-utans), puppies, kittens, wolves and goats. It must be taken into account that, although there is growing number of studies investigating object permanence in a wide range of species, most of them do not use specific tests to investigate the A-not-B error. In addition the methodologies vary immensely between studies. Although many studies use the basic set of tests by Uzgiris and Hunt (1989) that explore successive visible displacements, the precise set-up varies between studies and makes comparisons near impossible. It is therefore difficult to compare species with regards to the A-not-B error until a standard test with a defined number of repetitions and movements between targets is implemented.