Do dogs distinguish rational from irrational acts?

Range et al. (2007, Current Biology, 17, 868-872) found that dogs, Canis familiaris, copy others' means to achieve a goal more often when those means are the rational solution to a problem than when they are irrational. In our first experiment, we added a further control condition and failed to replicate this result, suggesting that dogs in the previous study may have been distracted in the irrational condition rather than selectively attending to the irrational nature of the action. In a second experiment, the demonstrator used an unusual means (an extended leg) to communicate the location of food, either rationally (her hands were occupied) or irrationally (she could have used her hand). Dogs succeeded in finding the food irrespective of whether the leg action was rational or irrational. Our results suggest that dogs do not distinguish rational from irrational acts, instead simply being proficient at monitoring human behavioural patterns.