The partner's country of origin also had no effect on the duration, unless they were from Turkey, where

 intercourse time was very short (3.7 minutes) compared to couples from other countries (Netherlands, Spain, England, and America).

Another thing that is surprising is the fact that the older the partner, the shorter the time to make love. This is contrary to common understanding (which older men may have made).

Why do we have to have long sex?

As an evolutionary researcher, all this talk about how long sex lasts makes me wonder: "Why does it have to be so long?". qqcitybet

Because, after all sexual intercourse the ultimate goal is to insert sperm into the vagina. Then why the excited movement in bed? Instead of inserting and removing the penis hundreds of times during sexual intercourse, why not just insert it once and then drink lemon?

Before you answer "Because sex is good!" please remember that the evolutionary process doesn't care about the fun stuff—the evolutionary process designed everything to be fun just because it helped our ancestors pass their genes on to future generations.

For example, even though we enjoy eating food, we won't chew food for five minutes just because we like it. It makes eating inefficient, and we evolve to understand that chewing food for too long is disgusting.

Why we have sex for so long is a tricky question for which there is no clear answer, but the clue may lie in the shape of the penis itself. In 2003, researchers discovered—using an artificial vagina, penis and sperm—that the tip of the head of the penis actually functions to pick up sperm that was previously in the vagina.

This suggests that the repetitive in-and-out motion of the penis is actually aimed at removing another man's sperm before ejaculation, to ensure that their sperm reaches the egg first.

It's no wonder that men feel pain when they keep pushing in their penis after ejaculating, because that means the movement risks removing their own sperm.

So what to do with this information? My advice is, you don't have to think too much when you're making love.