[1] Max Planck Inst Sci Human Hist, Dept Linguist & Cultural Evolut, Kahla Str 10, D-07745 Jena, Germany
[2] Friedrich Schiller Univ, Dept Gen Psychol, Steiger 3, D-07743 Jena, Germany
[3] Max Planck Inst Evolutionary Anthropol, Dept Dev & Comparat Psychol, Deutsch Pl 6, D-04103 Leipzig, Germany
[4] Univ Osnabruck, Inst Cognit Sci, Comparat BioCognit, Artilleriestr 34, D-49076 Osnabruck, Germany