Funding for this research was provided by:
European Social Fund (WND-POKL-01.03.06-00-041/08)
First Online: 22 June 2018
Compliance with Ethical Standards
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (the Polish Code of Professional Ethics for the Psychologist; Polish Psychological Association) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.
: Konrad Piotrowski declares that he has no conflict of interest. Anna I. Brzezińska declares that she has no conflict of interest. Koen Luyckx declares that he has no conflict of interest.