Men who grow up with only female siblings are 8.3% more likely to identify with the Republican Party, according to a recent study published in the Journal of Politics.
The report, titled Childhood Socialization and Political Attitudes, suggests that the presence of sisters apparently introduces the young boys to stereotypical gender roles at an early age, creating a higher likelihood that the boys identify with the conservative Republican Party when they grow up.
According to the report, "60.0% of boys responded that they helped with the dishes, compared to 82.2% of girls," showing that young girls are more likely to help out with female-associated household chores that are typically carried out by the mother. The brother internalizes the idea that females hold different responsibilities than their male counterparts of the family and carry this notion into their political beliefs later in life.
More than 3,000 individuals were surveyed for the study, which began in 1987 and followed the progress of children 10 years old and older.
The “sister effect” appears to only apply to males, and the report found no significant data to suggest that girls who grow up with sisters are more likely to become Republicans.