[1] Univ Vienna, Dept Cognit Biol, A-1090 Vienna, Austria
[2] Univ Vienna, Dept Basic Psychol Res & Res Methods, Social Cognit & Affect Neurosci Unit, A-1010 Vienna, Austria
[3] Emory Univ, Dept Anthropol, Behav Ecol Lab, Atlanta, GA 30322 USA
[4] Univ Zurich, Inst Evolutionary Med, Human Ecol Grp, CH-8057 Zurich, Switzerland
[5] Univ Vienna, Haidlhof Res Stn, A-2540 Bad Voslau, Austria
[6] Univ Vet Med, A-2540 Bad Voslau, Austria