Top 13 Sex Discoveries Of 2010

Sex isn't the first thing that comes to mind when we think about science. But, apparently science does a good deal of thinking about sex, as evidenced by these 13 fascinating sex-related discoveries researchers made in 2010. Read on to learn how everything from booty calls to skinny jeans affects our bedroom behavior. Sex, it seems, is so complex, we can't wait to learn more about it in 2011.

1.) Booty-call sex is awesome. Speaking on a strictly carnal level, a recent study of 300 college kids attending the University of West Florida proved that casual sex with a steady booty call is a recipe for phenomenal sex. Why? A mixture of both familiarity and wild-card excitement arouses your inner sexual go-getter. In contrast to relationships, a good booty calls depends on the quality of sex, which gives both participants more incentive to work harder.

2.) Wait till you're serious to have sex if you want a relationship to last. A study in The Social Science Research Journal confirmed what dating books have been telling us for eons: don't have sex too soon in a new relationship! Oh, the simplicity! Regardless, it's a rule many of us consistently muck up in those early, lustful stages of romance. Of the 648 people surveyed, 56 percent of those in long-lasting unions said they waited to be serious before having sex. Casual Sex: Good Or Bad? How About Both!

3.) Only 22 percent of married folks are "very satisfied" with their sex lives. But this one isn't all bad! According to a YourTango sex survey, 66 percent of married couples still have sex once a week (with 44 percent getting horizontal 3-4 times a week), but only 22 percent report being "very satisfied" with the their sex lives. So what's missing, we wonder? Perhaps even more sex—63 percent of the men say they want more sex than their partner. Sex Survey: 78% Of Marrieds Want Better Sex

4.) Men don't know when women orgasm. Either women need to stop faking or men need to pay closer attention. The National Survey of Sexual Health and Behavior report that 85 percent of men say their women climaxed during their last sexual encounter. In reality only 64 percent of women reported actually having an orgasm. A tip for men: women report reaching orgasm more quickly when their partners mixes it up in bed. 5 Fascinating Sex Facts From Largest Sex Survey

5.) A good job is good for your sex life. A University of Wisconsin study of 500 couples revealed that the most sexually satisfied couples also had the best jobs. So, logically, one would assume that those who work hard in life also overachieve in the bedroom. And, contrary to old stereotypes of the lonely, brainy spinster, a sociologist out of the University of California proved that the more educated a lady, the more likely she is to marry. Ambitious, Overachieving Women Have The Best Sex

6.) Sex makes your brain bigger. A band of researchers in Princeton aimed to find out if regular sex caused any physical changes in the brain. Lo and behold, rats who got laid on a regular basis experienced an increase in neurons in the hippocampus, the part of the brain associated with memory. The sex-happy rats also experienced more adult brain cell growth and connections between those cells. Sexually deprived rodents were more anxious and boasted higher levels of stress. Sex Makes Our Brains Bigger. Seriously.

7.) Nearly half of married women say their husband is not best sex they've ever had. Equal parts disheartening and refreshing, the results from an iVillage survey revealed that half of married women say their husband isn't the best sex they've ever had. The finding tells us that bedroom prowess isn't at the top of women's "must-have" list, but is that good news or bad news? Is Your Spouse The Best Sex You've Ever Had?

8.) A "promiscuity" gene has been discovered. After analyzing a group of sexually active young adults, researchers have concluded that there's a genetic tendency toward promiscuity. The desire to sleep around is linked with a dopamine receptor gene, DRD4, which is the same pleasure/reward gene to blame for a variety of thrill-seeking behaviors from gambling to drug use. Is DNA Really To Blame For Cheating, Promiscuity?

9.) Do sisters make men less sexually appealing? A study out of the University of Texas noticed that male rats with a plethora of sisters are less sexually appealing to lady rats. Why? Researchers aren't exactly sure, but noticed that boys in female-heavy litters had less girl suitors when ready to mate. However, aforementioned rats still got theirs—scientists noted that they still got girl rats pregnant at the end of the day. Do Sisters Make Men Less Appealing?

10.) A woman's sensitivity to touch linked with her ability to orgasm. Women who have greater sensitivity in their fingertips also orgasm more frequently than those who have delayed tactile responses. The study in The Journal of Sexual Medicine reports that there's a connection between physical touch and psychological development, meaning if your fingertips are self-aware, so is your whole body.

11.) Men with big bellies can last longer than their slimmer peers. Men with burgeoning bellies inadvertently have higher levels of the female sex hormone oestradial, which in turn affects the time elapsed before an orgasm. After a year-long study analyzing the BMI's and sex habits of 100 men, researchers found that fat guys lasted on average 7.3 minutes—slim men a mere 1.8 minutes. Why Men With Big Bellies Make Better Lovers

12.) A quarter of women would rather be thin than have good sex. Lack of orgasms and unsatisfying married sex aside, a British study says a quarter of women polled would sacrifice good sex if it meant fitting into their "skinny" jeans. Enough said.

13.) Is female sexual satisfaction still subconsciously taboo? A four-decade long study analyzed 4,000 men and women, hooked them up to devices to monitor their levels of excitement and then had them report on their arousal. An overriding trend? Women often downplayed their arousal. Men? Not so much.