Variable	Dimensions of the variable	Test	Z value	Significance level
Bullying clinical symptoms	Bullying	Pretest	0.692	0.724
	Bullying	Posttest	0.724	0.672
	Fighting	Pretest	1.024	0.245
	Fighting	Posttest	0.706	0.701
	Victimization	Pretest	0.892	0.404
	Victimization	Posttest	1.000	0.270
Anger control	External anger control	Pretest	0.568	0.903
	External anger control	Posttest	0.768	0.597
	Internal anger control	Pretest	0.758	0.614
	Internal anger control	Posttest	0.747	0.633
Emotional regulation	Self-blame	Pretest	1.173	0.127
	Self-blame	Posttest	1.015	0.254
	Blaming others	Pretest	0.900	0.393
	Blaming others	Posttest	0.805	0.537
	Acceptance	Pretest	0.653	0.788
	Acceptance	Posttest	0.692	0.313
	Refocus on planning	Pretest	0.955	0.321
	Refocus on planning	Posttest	0.852	0.462
	Rumination	Pretest	0.702	0.708
	Rumination	Posttest	0.701	0.709
	Catastrophizing	Pretest	0.894	0.401
	Catastrophizing	Posttest	0.958	0.318
	Putting into perspective	Pretest	0.834	0.490
	Putting into perspective	Posttest	1.017	0.252
	Positive refocusing	Pretest	1.104	0.175
	Positive refocusing	Posttest	0.716	0.685
	Positive reappraisal‎	Pretest	0.952	0.325
	Positive reappraisal‎	Posttest	1.041	0.229