The best places to find love — and lust — according to science

While friends were a source of introduction for all kinds of sexual partnerships at roughly the same rate (35–40 percent), family members were much more likely to introduce people to their future spouses than to future one-night stands. [Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives — How Your Friends' Friends' Friends Affect Everything You Feel, Think, and Do]

…the Chicago Sex Survey also collected data on where Americans met their partners. Sixty percent of the people in the study met their spouses at places like school, work, a private party, church, or a social club — all of which tend to involve people who share characteristics. [Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives — How Your Friends' Friends' Friends Affect Everything You Feel, Think, and Do]

The vast majority of these relationships have not lasted, especially for older workers. For workers who are over 50, 77 percent of those sexual relationships have ended. Younger people appear to have had more luck with 58 percent of people in the 18-24 age group reporting that they are still in their relationship. But perhaps that is just because they have been in the workplace such a short period of time the relationships are still new. [Barking Up the Wrong Tree]

Ten percent met their spouses at a bar, through a personal ad, or at a vacation spot, where there is more diversity but still a limited range of types of people who might be available to become future spouses. [Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives — How Your Friends' Friends' Friends Affect Everything You Feel, Think, and Do]

Of these "online daters," 43 percent — or nearly seven million adults — have gone on actual, real-life dates with people they met online, and 17 percent of them — nearly three million adults — have entered long-term relationships or married their online dating partners, according to a systematic national survey. [Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives — How Your Friends' Friends' Friends Affect Everything You Feel, Think, and Do]

…our findings suggest that conscientiousness is the trait most broadly associated with marital satisfaction in this sample of long-wed couples. [Barking Up the Wrong Tree]

And how people meet is also relevant to how quickly they have sex. In the Chicago study, those who met their partners through their friends were slightly more likely to have sex within a month of meeting than those who met through family members. A similar study conducted in France found that couples who met at a nightclub were much more likely to have sex within a month (45 percent) than those who met at, say, a family gathering (24 percent), which is not surprising since one typically does not have sex in mind at family events. [Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives — How Your Friends' Friends' Friends Affect Everything You Feel, Think, and Do]

Based on my study of Harvard undergraduates, the average number of romantic relationships over four years is less than one. The average number of sexual partners, if you're curious, is 0.5 per student. (I have no idea what 0.5 sexual partners means, but it sounds like the scientific equivalent of second base.) In my survey, I found that among these brilliant Harvard students, 24 percent are unaware if they are currently involved in any romantic relationship. [The Happiness Advantage: The Seven Principles of Positive Psychology That Fuel Success and Performance at Work]

Thirty percent of respondents engaged in sexual activity on their first encounter. Seventy-seven percent of respondents who met an online partner did not use condoms for their first sexual encounter. [Barking Up the Wrong Tree]

"Online dating can lead to feelings of accelerated intimacy," says Paige Padgett, PhD, the author of the study and a research associate in the UT School of Public Health's Division of Epidemiology and Disease Control. "You are able to disclose deeply personal information faster than you would if you were just meeting face to face for the first time," she explains… Because all of the nitty-gritty preliminaries are out of the way before you actually meet the person, Padgett believes that this may foster a sense of relationship before there is an actual relationship. [Barking Up the Wrong Tree]

…in one observational study at a bar where male humorous sexual remarks ran rampant, it was noted that the women who laughed at such jokes did indeed seem sexually interested in the men, whereas (obviously) the women who didn't laugh were not sexually interested. These humorous sexually loaded attempts could be conceptualized as a test to gauge interest and receptivity to a sexual encounter. [Mating Intelligence Unleashed: The Role of the Mind in Sex, Dating, and Love]