An audio essay on human nature, followed by an interview with primatologist Dr. Susan Cheyne. Susan is the co-director of the Borneo Nature Foundation International and the Borneo River Initiative for Nature Conservation and Communities, she is the Vice Chair of the IUCN Section on Small Apes, and she is also a Senior Lecturer at Oxford Brookes; she has been studying gibbons for about 27 years. Our conversation is wide-ranging, but centers on gibbons. We discuss gibbon locomotion, life among gibbons, the nature and function of gibbon song, gibbon violence, monogamy, and infanticide (and lack thereof), and other subjects. Enjoy. Dr. Cheyne's research: http://www.susancheyne.com IUCN Section on Small Apes: https://gibbons.asia/ Timestamps: 0:00 Are humans naturally monogamous? 17:27 Introducing today's subject and guest 20:25 Gibbon overview (interview starts) 31:57 Why do humans have twins? 34:02 A day in the life of a gibbon 38:57 Studying gibbons 40:37 Forgotten apes 44:06 Monogamy 1:09:27 Violence 1:11:34 Singing 1:17:49 Intelligence