Bonobos and chimpanzees that had been reared in socio-linguistically rich environments (i.e., lots of opportunities for complex communicative interactions with humans) performed significantly better in the pointing, vocalizing, and pointing-and-vocalizing conditions of an object-choice task than did chimpanzees that had been reared in standard laboratory settings. These results indicate that apes may have the potential for understanding declarative communication and this potential may be achieved in specific environments.