YOUNG AND JUVENILE CHIMPANZEES (PAN-TROGLODYTES) REACTIONS TO INTENTIONAL VERSUS ACCIDENTAL AND INADVERTENT ACTIONS

Chimpanzees were tested for their ability to discriminate between acci dental/inadvertent and intentional actions with equivalent adverse con sequences. Subjects were first trained to 'point' to human trainers in order to receive food rewards. In Experiment 1, six 5-year-old subjec ts were alternately presented with two unfamiliar human actors. In con dition I, each actor either started to hand a cup of juice to the trai ner but then pulled it back and intentionally poured it onto the floor , or accidentally spilled it while handing it to the trainer. In condi tion 2, the actors either accidentally spilled it as above, or aggress ively threw the juice onto the floor. The subjects were then presented with both actors and were allowed to choose between them. In Experime nt 2, seven 6-7-year-old chimpanzees were confronted with unfamiliar a ctors who either (a) intentionally withheld and consumed food intended for the subjects, (b) attempted to hand the intended food to the subj ects but were victimized by a third party who consumed the food, or (c ) always succeeded in delivering the food to the subjects. In general. the subjects showed little evidence of using the accidental/inadverte nt versus intentional distinction in their choices between the actors, although they did display some evidence of favoring the actor involve d in the most passive role in both conditions in Experiment 1. (C) 199 8 Elsevier Science B.V.