Białecka-Pikul, Marta
Stępień-Nycz, Małgorzata
Sikorska, Iwona
Topolewska-Siedzik, Ewa
Cieciuch, Jan
Article History
Received: 11 February 2019
Accepted: 14 May 2019
First Online: 27 May 2019
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.
: The project was approved by the Ethical Board of the Institute of Psychology, Jagiellonian University and has been performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments. The authors followed the ethical standards set by the SRCD for the presented research.
: School principals and teachers gave their clearance and each participant and their parents provided the informed consent before participation in the study.