; including materials and instruction that are inclusive of race, ethnicity, languages, cultural background, religion, sex, gender identity, sexual orientation, and different abilities. (8) Evidence-based The term evidence-based , when used with respect to sex education instruction means a sex education program that has been proven through rigorous evaluation to be effective in changing sexual behavior or incorporates elements of other programs that have been proven to be effective in changing sexual behavior. (9) Gender expression The term gender expression , when used with respect to a sex education program, means the expression of one’s gender, such as through behavior, clothing, haircut, or voice, and which may or may not conform to socially defined behaviors and characteristics typically associated with being either masculine or feminine. (10) Gender identity Except with respect to section 7, the term gender identity , when used with respect to a sex education program, means the gender-related identity, appearance, mannerisms, or other gender-related characteristics of an individual, regardless of the individual’s designated sex at birth including a person’s deeply held sense or knowledge of their own gender; such as male, female, both or neither. (11) Inclusive The term inclusive , when used with respect to a sex education program, means curriculum that ensures that students from historically marginalized communities are reflected in classroom materials and lessons. (12) Institution of higher education The term institution of higher education has the meaning given the term in section 101 of the Higher Education Act of 1965 ( 20 U.S.C. 1001 ). (13) Medically accurate and complete The term medically accurate and complete , when used with respect to a sex education program, means that— (A) the information provided through the program is verified or supported by the weight of research conducted in compliance with accepted scientific methods and is published in peer-reviewed journals, where applicable