Table 4.

| Grade differences in Internet addition, aggression, physical aggression, verbal aggression, anxiety, anger, hostility, anxiety and depression.

	Total (N = 999)	Grade 7 (n = 566)	Grade 8(n = 4 33)
	M(SD)	M(SD)	M(SD)	t	p
Internet addiction	7.85(6.73)	7.96(6.45)	7.71(7.09)	0.59	0.552
Aggression	72.78(18.07)	72.25(18.08)	73.47(18.06)	−1.06	0.289
Physical aggression	18.69(5.32)	18.37(5.21)	19.12(5.44)	−2.21	0.028⁎
Verbal aggression	12.82(3.82)	12.67(3.80)	13.01(3.85)	−1.39	0.166
Anger	15.27(5.61)	15.40(5.60)	15.09(5.62)	0.88	0.379
Hostility	20.82(6.71)	20.85(6.66)	20.78(6.79)	0.18	0.860
Anxiety	35.38(6.58)	34.89(6.34)	36.02(6.84)	−2.68	0.007⁎⁎
Depression	42.23(6.90)	42.18(7.08)	42.30(6.66)	−0.26	0.792

Note.

^⁎p < 0.05.

^⁎⁎p < 0.01.