ABSTRACT
Participants and procedure Participants were recruited through day care centres and elementary and secondary schools in the capital city of Saxony-Anhalt, Germany. Eligibility criteria were defined to include only couples (a) who had an oldest child between 3 and 5 years (day care centres), 6 and 10 years (elementary schools) or 11 and 15 years (secondary schools); (b) who lived together with this oldest child in one household (either married or in cohabitation) and (c) of whom both members were willing to participate.
