Comment on “Differential Sensitivity to Human Communication in Dogs, Wolves,

human signals contributes to the emergence of a spatial perseveration error (the A-not-B error) for locating objects. Here, I argue that the authors ’ conclusion was biased by two confounding factors: the use of an atypical A-not-B search task and an inadequate nonsocial condition as a control. Ten-month-old infants, after having founda hidden object at a first hiding location(A), persistently continue to search at location A even after observing the object be-ing hidden at a second location (B). This persev-erative error (called the A-not-B error) is typical of Stage 4 of Piaget’s sensorimotor period of cognitive development but rapidly vanishes at 12 months of age when the infants reach Stage 5 (1). Topál et al. (2) recently reported that domestic dogs, but not wolves, make theA-not-B error, but solely if humans give them ostensive-referential cues during the manipulation of the object (i.e., looking back and forth between the hiding locatio