1. Primate Kin Selection group, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
2. Department of Biology, Norwegian University of Science & Technology, 7491 Trondheim, Norway
3. Behavioural Ecology group, Institute of Biology, University of Leipzig, 04103 Leipzig, Germany
4. Welfare and Cognition group, Cognitive Neuroscience Laboratory, German Primate Center, 37077 Göttingen, Germany
5. Leibniz-ScienceCampus Primate Cognition, German Primate Center & Georg-August-University, 37077 Göttingen, Germany