[1] Univ Edinburgh, Sch Philosophy Psychol & Language Sci, Dept Psychol, Edinburgh, Midlothian, Scotland
[2] Scottish Primate Res Grp, Edinburgh, Midlothian, Scotland
[3] Ctr Cognit Ageing & Cognit Epidemiol, Edinburgh, Midlothian, Scotland
[4] Georgia State Univ, Neurosci Inst, Atlanta, GA 30303 USA
[5] Yerkes Natl Primate Res Ctr, Div Dev & Cognit Neurosci, Atlanta, GA USA
[6] Smithsonian Inst, Natl Zool Pk, Washington, DC 20560 USA
[7] Univ Stirling, Psychol Div, Stirling, Scotland
[8] Kyoto Univ, Wildlife Res Ctr, Kyoto, Japan
[9] Natl Inst Environm Studies, Wildlife Genome Collaborat Res Grp, Tsukuba, Ibaraki, Japan
[10] Kyoto Univ, Inst Adv Study, Kyoto, Japan
[11] Kyoto Univ, Primate Res Inst, Inuyama, Aichi, Japan
[12] Japan Monkey Ctr, Inuyama, Aichi, Japan
[13] Univ Arizona, Dept Psychol, Tucson, AZ 85721 USA
[14] Lincoln Pk Zoo, Lester E Fisher Ctr Study & Conservat Apes, Chicago, IL USA