Table 2.

Means and standard deviations (SD) of the Strengths and Difficulties Questionnaire (SDQ) scales

		11 to 14 years		15 to 17 years
	Total	Male	Female	Male	Female
Prosocial behavioura	8.1 ± 1.8	7.9 ± 2.0	8.4 ± 1.6	7.5 ± 2.1	8.2 ± 1.8
Hyperactivityb	3.6 ± 2.2	3.1 ± 2.2	3.1 ± 2.1	3.9 ± 2.2	4.1 ± 2.2
Emotional symptomsabc	3.0 ± 2.1	2.3 ± 2.2	3.1 ± 2.0	2.5 ± 2.0	3.7 ± 2.1
Conduct problemsb	2.0 ± 1.5	3.0 ± 1.7	2.8 ± 1.4	3.0 ± 1.5	3.1 ± 1.5
Peer problems	1.8 ± 1.7	1.9 ± 2.0	1.7 ± 1.6	1.9 ± 1.8	2.0 ± 1.6

^aP <0.05 for gender differences; ^bP <0.05 for age differences; ^csignificant gender/age interaction.