1. Division of Reproductive Endocrinology, University Hospital Zurich, Frauenklinikstr. 10, CH 8091 Zurich, Switzerland
2. Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
3. Department of Psychiatry, Weill Medical College of Cornell University, New York, NY 10065, USA
4. Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich, 8006 Zurich, Switzerland
5. Institute of Veterinary Physiology, University of Zurich, 8057 Zurich, Switzerland