INTERSPECIES OBJECT EXCHANGE - BARTERING IN APES

Of 114 chimpanzees, 55 exchanged non-edible items for food items, indi cating a proportion significantly greater than chance. In addition, th ose animals which did exchange were more likely to when encouraged by human solicitation. These behaviors suggest a social significance beyo nd simple behavioral economics in processing information about giving and getting. Further, these and several observed manipulations of rewa rd-getting suggest that chimpanzees may also have a limited understand ing of the expression and manipulation of the relative values of certa in items. The behavioral foundations of and theoretical implications f or primate social cognition and economic psychology are discussed. (C) 1998 Elsevier Science B.V.