Funding for this research was provided by:
Nationaal Regieorgaan Onderwijsonderzoek (40.5.18540.081)
Received: 11 December 2020
Accepted: 16 December 2020
First Online: 19 January 2021
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: The study was approved by the Ethical Internal Review Board of one of the participating universities (Utrecht University), and the privacy and confidentiality of students’ data were guaranteed.
: A passive consent procedure was used. If students did not want to participate, or their parents disagreed with their children’s participation, they were asked to send a reply card or email within two weeks. Students were allowed to opt out participation any time.