Sex studies

When did you sex studies your virginity? Do you have a comfortable couch? Do you reach orgasm every time? How many sex partners have you had?

Whether it’s penis size, papillomavirus risk, or profligate pregnancies, it’s good to know the numbers. Check out these stats to see if you are well within the sexual mean — or if you’re off the charts. But there’s also an argument for men’s biological drive to perpetuate their genes: An 18th-century Russian woman holds the world record for having birthed the most children: 69, which she had over the course of 27 pregnancies that included sixteen pairs of twins, seven sets of triplets, and four sets of quadruplets. No matter what those, ahem, movies might suggest, in the United States, the average erect penis is five to seven inches long, and four to six inches in circumference. Approximately 5 percent of 40-year-old men and between 15 to 25 percent of 65-year-old men experience erectile dysfunction. The average male loses his virginity at age 16.

And a new study shows that genetics may be a factor: inherited traits, such as impulsivity, can make a person more or less willing to have sex at an earlier age. About one out of 10 married adults — 12 percent — say that they typically sleep alone. While 75 percent of men always reach orgasm during sex, only 29 percent of women report the same. In addition, most women are unable to climax through vaginal intercourse, instead needing clitoral stimulation.

Two-thirds of college students have been in a “friends with benefits” relationship, citing the lack of commitment required as the main advantage to such an arrangement. 7 percent said they had intercourse only, while 8 percent said they did everything but have intercourse. Two-thirds of women who had their first baby between 2001 and 2003 worked during their pregnancy, and 80 percent of those women worked within one month or less of giving birth. At least 50 percent of sexually active men and women will have a genital HPV infection at some point in their lives. HPV can cause genital warts, and high-risk can cause cervical and other cancers.