Table 2.

Group differences of study variables between junior school versus high school students.

Variables	Junior School Students		High School Students		t	Cohen’s d
	Mean	SD	Mean	SD
Age	13.18	1.00	16.34	1.02	—	—
Father’s education level	2.62	0.74	2.37	0.72	5.84 ***	0.34
Mother’s education level	2.46	0.78	2.15	0.71	7.08 ***	0.42
Peer attachment	2.78	0.64	2.78	0.57	0.08	0.00
POS	4.01	0.83	4.09	0.73	−1.67	0.10
NEG	3.42	0.76	3.39	0.71	0.77	0.04
Aggressive behavior	1.54	0.81	1.62	0.83	−1.55	0.10

Note: n = 1171. POS, self-efficacy in expressing positive emotions; NEG, self-efficacy in managing negative emotions; SD, standard deviation. *** p < 0.001.