https://www.sciencedaily.com/releases/2020/12/201201084752.htm > In contrast, states with higher gender equality, measured by the number of women in the labor force, were early adopters. > Washington State University sociologists Thomas Rotolo and Michael Lengefeld, a recent WSU Ph.D. now at Goucher College, analyzed the wave of youth concussion laws from 2007 to 2014, specifically looking at return-to-play guidelines: a mandated 24-hour wait period before sending a player with a possible concussion back on to the field.