Margaret Kerr is Professor of Psychology at Örebro University, Sweden.

Håkan Stattin is Professor of Psychology at Uppsala and Örebro Universities, Sweden.

Rutger C.M.E. Engels is Professor of Developmental Psychopathology, Radboud University Nijmegen, The Netherlands.

Geertjan Overbeek is Associate Professor at the Department of Developmental Psychology, Utrecht University, The Netherlands.

Anna-Karin Andershed is Assistant Professor of Psychology at Örebro University, Sweden.