The next time you act totally out of character, blame biology. From bad choices in men to even worse choices in clothing, you can tell yourself it's your ovaries' fault.
You Choose Bad Boys
There's a reason you're pining after Shia Labeouf types at the same time each month. A recent study noticed that when ovulating-around day 11 of your cycle, which coincides with peak fertility-women chose bad boys over dependable ones. Researchers asked women during high and low fertility to look at dating profiles of "sexy, rebellious" men versus "reliable" ones. When ovulating, the ladies believed the hot guys would be better husbands and dads than the loyal ones. They repeated the study with live actors and found the same results. So the next time you go home with an attractive a-hole while your friends eye-roll in disbelief, check your cycle.
Related: Rundown on exercise, PMS and period pain
You Wear Tighter Clothes
File this new finding under WTF: Women tend to buy racier outfits during ovulation, according to a study published in the Journal of Consumer Research. Ladies at different phases of their cycle were shown pictures of other women before choosing which clothes to buy. The ovulating women, who were shown the most attractive pics, chose more revealing attire (to stand out from the competition). Their non-ovulating counterparts didn't.
You Shop Til You Drop
Add this to your list of choices you'll soon regret: Women were more likely to splurge 10 days before their periods began. After surveying almost 500 women, a study found that over half of the women who were pre-period recently overspent by more than $50. The reason? Women go impulse shopping to help with the PMS blues. Our advice: Stick to cheaper forms of happiness, like the beautiful black hole made up of shirtless Ryan Gosling Tumblrs.
Guys Talk To You Differently
Another weird side effect of your fertility? Men start to seem uber-funny. A study found that the more fertile you are (during ovulation, in other words), the more men mix up the way they talk to you. Researchers think guys used varied language in order to stand out to a woman, and you know, hopefully mate with her. So don't be too impressed with that awesome pick-up line he just used if you're ovulating. See if he wows you with his wit a week later.
Your Gaydar Improves
Now you have a tool to help you figure out if that impeccably-dressed dude is flirting with you just to get to your best guy friend. After showing 80 pictures of gay and straight men, ovulating straight women were more likely to spot a gay dude than women at any other point in their cycle. Lesson learned: Use your cycle the next time you're man hunting.
Related: Tame the PMS beast!
Your Voice Changes
As if the bloating, stomach pain, and mood swings of PMS doesn't cause enough crap, Mother Nature's monthly gift also gives you an unattractive voice, says science. After men listened to female voice recordings over the course of a menstrual cycle, they guessed when she was on her period correctly 35 percent of the time-10 percent higher than predicted by chance. In another part of the study, another male group were asked to choose the most "unattractive" voice and also chose the period voice accurately 34 percent of the time. So what was so verbally hideous? Menstrual voices sounded lower in mood, quality, and pitch, according to the researchers.
You Spot Snakes Faster
How's this for a special Girls Scout badge? A recent study found that women were quicker to detect photos of snakes while ovulating than women at other points in their cycle. Turns out fluctuating hormones can influence your amygdala, the part in your brain that triggers fear. They tested this with non-threatening flowers too and found no change in response time. This makes sense if subconsciously you're protecting yourself at your most fertile time. Lesson learned: time your next camping trip a week before your period and impress everyone with your reflexes.
Related: A man's guide to a woman's PMS
You Have Sexier Fantasies
In the name of science, 27 fun and fearless women were recruited to record their sexual daydreams in an online diary for a month. On average, the ladies reported 0.77 fantasies a day. But in the three days near ovulation (researchers made the women take a urine test to detect where they were in the cycle), the fantasies increased to 1.3 per day and were more arousing. You know what that means. The week before your period, make a private appointment. Where: your locked bedroom. Who: your sexiest lingerie. What: your dog-eared copy of 50 Shades.
You're More Susceptible to Infection
You can add getting sick to the list of crappy PMS side effects. After treating mice with the sex hormone estradiol, a recent study in the Journal of Leukocyte Biology discovered that they were more likely to be infected with sexually-transmitted infections during ovulation. Why the sudden dip in your immune system? Scientists theorize it's an evolutionary adaptation that allows male sperm to survive in your system long enough to fertilize an egg. Now that you know, get enough sleep and take extra vitamins mid-cycle. We also suggest using this study to your advantage, as in "Babe, I'd looooooove to go to that monster truck festival with you, but science says I should hang low this week. Have fun without me!"
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