Instructional materials adopted under this chapter shall, where appropriate, be designed to impress upon the minds of the pupils the principles of morality, truth, justice, patriotism, and a true comprehension of the rights, duties, and dignity of American citizenship, and to instruct them in manners and morals and the principles of a free government. The State Board of Education shall endeavor to see that this objective is accomplished in the evaluation of instructional materials for educational content in appropriate subject areas.