In 2013, a study in Psychological Science suggested a link between women's menstrual cycle and their religious and political orientation. The researchers indicated that a woman's relationship status affects her decisions.

The study, conducted by researchers at the University of Texas at San Antonio, found that single women tend to be more liberal (socially), less religious and were more likely to vote for Barack Obama during ovulation. The study also found that women in committed relationships were typically conservative (socially), more religious and were more likely to vote for Obama's election opponent, Mitt Romney.

A new study of 750 women found no evidence of a link between a woman's menstrual cycle and her politics. The study, published in the journal PLoS One, was conducted by researchers from Brunel University London.

"In summary, our data offer little support for the proposal that there is a substantial, politically significant, effect of menstrual cycle phase on political attitude," researchers Isabel M. Scott and Nicholas Pound wrote.

Scott and Pound began their research before the 2013 study was published, so their methodology isn't an exact replica. "In the present study, one way we assessed political conservatism was by measuring the more abstract moral foundations that, according to research building on moral foundations theory underlie observed differences with political liberals and conservatives. Our measures therefore, are arguably less susceptible to preferences shifts associated with preferences for contemporary political figures," they wrote.

Scott and Pound said their findings highlight the importance of replication in science. The wrote: "Replication is of course essential for the advancement of scientific knowledge and consequently it would be helpful for future research to continue to address the extent to which previously reported menstrual cycle effects on other behaviours are robust. "