Developmental changes in achievement motivation Running head: DEVELOPMENTAL CHANGES IN PE Developmental Changes in Achievement Motivation and Affect in Physical Education: Growth Trajectories and Demographic Differences

We examined changes in student achievement goals, perceptions of motivational climate and affective responses in secondary school physical education. Greek junior high school students (N = 394; 191 males and 203 females) responded to a multi-section questionnaire twice a year from the ages of 12 -15 years. Multilevel modeling analyses showed significant linear decreases in perceptions of task-involving teacher climate, task and ego goal orientations, which were somewhat reversed by the beginning of the last year of the junior high school. Significant linear decreases were also observed for enjoyment whereas there were significant linear increases for perceptions of ego-involving climate and boredom. There was significant variability in the intercepts and/or average changes over time for all variables and, therefore, we included demographic and theoretical predictors in an attempt to account for such variations. The results indicated that decreases in adaptive motivation over time vary across students and in some cases may be tackled by fostering a task-involving teacher climate.