In surveys conducted in 2002 and 2011, pollsters at Gallup found that members of the American public massively overestimated how many people are gay or lesbian

In 2002, a quarter of those surveyed guessed that upwards of a quarter of Americans were gay or lesbian (or "homosexual," the third option given). By 2011, that misperception had only grown, with more than a third of those surveyed now guessing that more than 25% of Americans are gay or lesbian. Women and young adults were most likely to provide high estimates, approximating that 30% of the population is gay. Overall, U.S. adults, on average, estimate that 25% of Americans are gay or lesbian, Gallup found. Only 4% of all those surveyed in 2011 and about 8% of those surveyed in 2002 correctly guessed that fewer than 5% of Americans identify as gay or lesbian. The Williams Institute at UCLA School of Law, a gay and lesbian think tank, released a study in April 2011 estimating based on its research that just 1.7% of Americans between 18 and 44 identify as gay or lesbian, while another 1.8% - predominantly women - identify as bisexual. A Centers for Disease Control and Prevention survey of women between 22 and 44 that questioned more than 13,500 respondents between 2006 and 2008 found very similar numbers: Only 1% of the women identified themselves as gay, while 4% identified as bisexual. The Williams Institute found that, overall, an estimated 8.2% of the population had engaged in some form same-sex sexual activity. Put another way, 4.7% of the population had wandered across the line without coming to think of themselves as either gay or bisexual. Other studies suggest those individuals are, like the bisexuals, mainly women: The same CDC study that found only 1% of women identify as lesbian, for example, found that 13% of women reported a history of some form of sexual contact with other women. Overall, there have been fewer than 75,000 state-sanctioned same-sex marriages in the United States since they began to be permitted less than a decade ago, according to an estimate by Marriage Equality USA. Over the eight years since Massachusetts became the first state to legalize same-sex marriage in May 2004, 18,462 same-sex couples married in the Bay State. Another 18,000 were estimated to have wed in California during the few months before Proposition 8 passed in 2008, banning future ones; those marriages remain on the books, as the proposition was not retroactive. It's not totally clear how many same-sex marriages have taken place in New York, Connecticut, Vermont, New Hampshire, and the District of Columbia, the other jurisdictions where it is permitted.