1 Davis School of Gerontology, University of Southern California, Los Angeles, USA.
2 Department of Psychology, University of Southern California, Los Angeles, USA.
3 Faculty of Medicine and University Hospital Cologne, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Cologne, Cologne, Germany.
4 Department of Psychological Science, University of California Irvine, Irvine, USA.
5 Davis School of Gerontology, University of Southern California, Los Angeles, USA. mara.mather@usc.edu.
6 Department of Psychology, University of Southern California, Los Angeles, USA. mara.mather@usc.edu.