The primary reason that girls made up only 50% of school athletics in 1970 was the prevalence of gender bias and unequal opportunities for girls in sports. Traditional societal norms and beliefs often marginalized girls' participation in sports, stereotyping them as physically inferior or prioritizing other activities for girls. Institutional and systemic barriers, such as limited funding, lack of proper facilities, unequal coaching, and fewer team options, further restricted their access to athletic opportunities. Additionally, there was a lack of awareness and recognition of the benefits of female participation in sports, both for physical fitness and personal development. These factors contributed to the gender disparity in school athletics during that time.
