A comparison ofCebus albifrons andSaimiri sciureus on oddity performance

Four squirrel and four Cebus monkeys were trained on five-trial oddity problems. Two of each species were then given problems where the odd object was reversed randomly on Trials 2, 3, or 4. They were then given one-trial oddity problems. All reached criterion in initial training. One Cebus reached criterion in reversal training, but the others showed significant improvement. All monkeys receiving one-trial oddity training responded correctly on 80% of 40 consecutive problems within 80 problems. No reliable differences were seen between the species. Discussion concerned the measures required to conclude that an animal has the oddity principle, and it was suggested that no nonprimate has been shown to master oddity.