... Teacher Education School at Helsinki University (education group, n = 96) and Puistola Primary School (control group, n = 79). The students from the first- mentioned school were chosen to be the education ... education would depend on the age at which the lessons are attended. The education group was further divided into two subgroups, as the second wave of education was given only to 2/3 of the education ... baseline) from two schools in Helsinki area participated in the study. At the completion of the study at two years, the groups consisted of 96 (education, school one) and 79 (control, school two) students....