A favourite tactic of sexists looking to discredit people with vaginas is to tell them that whatever they're thinking or feeling is merely a result of their periods. Exhibit A: Donald Trump's jab that Megyn Kelly had "blood coming out of her wherever." Exhibit B: A letter to the Sun Gazette claiming to be "critical of Hillary Clinton and her health" because "what if that time of month comes and she is sick at the same time?" Anyone who menstruates already knows this use of periods as an insult is totally baseless. Still, it's always nice to have science to confirm your lived experiences — and a new study in Frontiers in Behavioural Neuroscience does just that.
Brigitte Leeners, MD, professor of reproductive endocrinology at University Hospital Zurich, and her colleagues tested three cognitive skills at four times of month in 88 women, 68 of whom were assessed for two months, Healthline reports. They measured their ability to remember things they'd seen, to pay attention to visual and auditory information at the same time, and to exert conscious control over their thoughts. They also determined their levels of estrogen, progesterone, and testosterone, the sex hormones that vary throughout your cycle. Overall, they saw no correlation between the women's hormone levels and any of these abilities.
The authors also found that previous research suggesting a correlation between the menstrual cycle and cognitive abilities suffers from "inflated effect sizes and probable false-positive findings due to methodological biases and random variance."
This study debunks the idea of "period brain" — i.e., that people are less competent on their periods. Although everyone's body is different and it's possible that some could experience this, it's not reasonable to assume someone's work will suffer during their period, Leeners told CBS. "In most women, the menstrual cycle does not influence cognitive performance in a negative way."