Background: Aggression is one of the factors underlying immoral behaviors. Thinking education can prevent aggression. The goal of this research, developing a thinking instructional design model based on Vigotsky's Social-Cultural Theory and assessing its impact on reducing aggression is one of the factors underlying students' immoral behaviors.
Method: The research method is mixed and the research design is a sequential exploration mix. The theme analysis method was used in the qualitative part and the experimental method was used in the quantitative part. The qualitative section community consisted of scientific texts from 1930 to 2019 that were selected by purposeful sampling and consisted of 18 books and 40 articles. Six experts were also interviewed and the model was developed. In the quantitative section, the developed model was sent to 15 experts who were purposely selected. Also, 30 students were selected from girl students’ schools in Asadabad by single-stage cluster sampling and they were divided into two experimental and control groups and received 9 sessions of 75-minute thinking instruction. Quantitative section tools included a researcher-made questionnaire for model validation with a reliability coefficient of 0.72 and the rating scale for measuring immoral behaviors was 0.74. The statistical method was a single sample t-test and an independent t-test.
Results: Thinking instructional design model was developed and validated in thematic network method, with 3 global themes and 15 organizing themes. In the first hypothesis, namely, aggression reduction, the calculated t value is 2.899 with a degree of freedom of 28 at P <0.05 is meaningful. In the second hypothesis, namely reduction of immoral behaviors, the calculated t value of 13.2 with a degree of freedom 4, is significant at P <0.05.
Conclusion: Thinking instruction according to the model developed, it resulted in a decrease in aggressive behaviors and consequently a decrease in the immoral behaviors of female students.