Funding for this research was provided by:
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (400.17.601, workpackage 3)
Received: 8 March 2019
Accepted: 16 May 2019
First Online: 7 June 2019
Ethics approval and consent to participate
: The independent Ethical Committee Psychology of Leiden University approved the design of this study (number CEP18–1105/419). Students and parents gave written active informed consent for participation of the student. Additionally, parents and trainers gave written active informed consent for their own participation.
: Not applicable.
: The authors declare that there are no competing interests with regards to the study.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.