Actually, most people do. You should probably come up with statistics before you start down a Charlie Martel trip, too.There are nearly 93 million unmarried Americans over age 18, representing roughly 42% of the adult population. - U.S. Census Bureau. “America’s Families and Living Arrangements: 2007.”There are more than 56 million American adults who have always been single, representing roughly 60% of the adult unmarried population. - U.S. Census Bureau. “America’s Families and Living Arrangements: 2007.”Lets do some math here... Of the 58% who are married, half of them will end in divorce, leaving 29% of married couples who have chosen a life long partner.50% percent of first marriages, 67% of second and 74% of third marriages end in divorce, according to Jennifer Baker of the Forest Institute of Professional Psychology in Springfield, Missouri.”
Of the 42% that are unmarried, 40% of them are already divorced, and of the remaining 25%, at least 20% will remain unmarried. The remaining 20% of the population will marry at some point, but half of them will get divorced, so the percent of people who choose a life long partner and stick with them will increase from 29% to 39%, still well below the 50%.
Even if we were to suppose that the entire 5% of the population who remains unmarried were in life long gay domestic partnerships, it would only bring the number up to 44%.
In conclusion, when it comes to a "natural tendency" for choosing lifelong partnerships, people FAIL. Humans are not a creature that mates for life in most cases. We like to mate for a few years, then get bored an move on.