Updates are available Correction dated 2021-04-14

Article History

Received: 24 January 2020

Accepted: 28 September 2020

First Online: 9 November 2020

Change Date: 14 April 2021

Change Type: Correction

Change Details: A Correction to this paper has been published:

Change Details: https://doi.org/10.1186/s42409-021-00024-9

Ethics approval and consent to participate

: Prior to each data collection, one of the researchers met with the teachers and headmasters, presented the project’s goals and research questions in detail, and received the consent of the school authorities and individual schools’ staff. The students and parents in Switzerland had the possibility to opt-out of the study, whereas in Poland, an opt-in written form signed by the parents was required. In Switzerland, only 10 out of 18 cantons contacted agreed that their schools participate in the survey. We did not encounter this problem in Poland, because a mandate received from the federal level allowed direct contact with the individual schools.

: Not applicable.

: Not applicable.