(Times of Israel) For millennia, observant Jewish couples have followed the laws of taharat hamishpaha, or family purity, which include refraining from sex during a woman’s period, and for a full seven days after the woman is niddah.

And, according to a new study to be presented at the Second Annual Conference on Judaism and Evolution at the Schechter Institute of Jewish Studies on Sunday, those couples may be on to something.

Rick Goldberg, an independent scholar based in Austin, Texas, and Dr. Orit Barenholz of Hadassah oversaw a study, in which 19 religiously observant, married Jewish men provided saliva swabs twice a week for three months, so their testosterone levels could be monitored.

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