The STEM fields are rapidly becoming the most in-demand and lucrative in the world. Despite this demand, at almost every step of the STEM education ladder women and girls walk away. By middle school many girls are ambivalent toward these fields, and by the end of high school fewer girls than boys plan to pursue STEM studies in college. Women who do graduate with a STEM degree enter a workforce that is historically unfriendly to them. And from there stereotypes, gender bias , and the hostile climate of academic departments and workplaces continue to block women’s participation and progress .