– Having an opposite sex sibling makes educational choices more gender-stereotypical for both genders.
– Having an opposite sex sibling reduces women’s probability to enroll in any STEM program after compulsory schooling by two percent and to complete a STEM college major by nine percent.
– Men with opposite sex siblings are more likely to enroll in and complete STEM education, but are not more likely to succeed in high-level STEM programs.
– Parents with mixed sex children gender-specialize their parenting more and spend more quality time with their same sex child than parents with same sex children.
– Young boys with an opposite sex sibling are exposed to more gender-stereotypical behavior within the family than boys with a same sex sibling.
– Having a gender-discordant sibling induces more men to enroll in a STEM program that is at a higher level of education than the highest level of education they ever complete. This implies that these men are more likely to drop out of a STEM program and never complete another field of study at the same educational level. There is no effect on drop-out for women.