Lemurs and macaques show similar numerical sensitivity
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We investigated the precision of the approximate number system (ANS) in three lemur species (Lemur catta, Eulemur mongoz, and Eulemur macaco flavifrons), one Old World monkey species (Macaca mulatta) and humans (Homo sapiens). In Experiment 1, four individuals of each nonhuman primate species were trained to select the numerically larger of two visual arrays on a touchscreen. We estimated numerical acuity by modeling Weber fractions (w) and found quantitatively equivalent performance among all four nonhuman primate species. In Experiment 2, we tested adult humans in a similar procedure, and they outperformed the four nonhuman species but showed qualitatively similar performance. These results indicate that the ANS is conserved over the primate order.
KeywordsNonhuman primates Numerical cognition Comparative psychology Number discrimination Weber fraction Prosimians
We thank the Duke Lemur Center, Monica Carlson, and the many research assistants who assisted with this research. We thank members of the Brannon laboratory for their helpful discussion of these data. This work was supported by a National Science Foundation CAREER award (No. 0448250) to Elizabeth M. Brannon.
Conflict of interest
The authors declare that they have no conflict of interest.
The experiments reported here comply with the current laws of the United States of America.
- Beran MJ, Johnson-Pynn JS, Ready C (2011b) Comparing children’s (Homo sapiens) and chimpanzees’ (Pan troglodytes) quantity judgments of sequentially presented sets of items. Curr Zool 57:419–428Google Scholar
- Best NG, Cowles MK, Vines K (1995) CODA* convergence diagnosis and output analysis software for Gibbs sampling output Version 0.30. MRC Biostatistics Unit, CambridgeGoogle Scholar
- Fichtel C, Kappeler PM (2010) Human universals and primate symplesiomorphies: Establishing the lemur baseline. In: Kappeler PM, Silk J (eds) Mind the gap: tracing the origins of human universals. Springer, HeidelbergGoogle Scholar
- Fisher RA (1930) The genetical theory of natural selection. Oxford University Press, OxfordGoogle Scholar
- Gelman A, Hill J (2007) Data analysis using regression and multilevel/hierarchical models. Cambridge University Press, CambridgeGoogle Scholar
- Gelman A, Carlin JB, Stern HS, Rubin DB (2004) Bayesian data analysis. Chapman & Hall/CRC, Boca Raton, FLGoogle Scholar
- MacLean E, Sandel A, Bray J, Oldenkamp R, Reddy R, Hare B (2013) Group size predicts social but not nonsocial cognition in lemurs. PLos One 8(6):e66359. doi: 10.1371/journal.pone.0066359
- Merritt D, MacLean E, Crawford JC, Brannon EM (2011) Numerical rule-learning in ring-tailed lemurs (Lemur catta). Front Comp Psychol 2(23):1–9Google Scholar
- Tattersall I (1982) The primates of Madagascar. Columbia University Press, New YorkGoogle Scholar