More Say 'Nature' Than 'Nurture' Explains Sexual Orientation

WASHINGTON, D.C. -- Half of Americans in Gallup's 2018 Values and Beliefs poll say that being gay or lesbian is a trait from birth, easily eclipsing the 30% who believe it is a product of upbringing and environment. This is consistent with findings over the past few years. Another 10% say both explanations play a role, while 4% attribute being gay to something else and 6% are unsure.

When Gallup first asked this "nature vs. nurture" question in 1977, a majority of U.S. adults (56%) said being gay or lesbian was due to people's upbringing and environment, and only 13% saw it as a birth trait. Attitudes didn't shift markedly until after 1989. Between 1989 and Gallup's next update in 1996, the percentage believing sexual orientation is determined at birth jumped from 19% to 31%, and reached 40% by 2001. Opinion remained steady for the next 12 years, as Americans were roughly split between the two positions. Since 2012, the percentage assigning sexual orientation to nature rather than nurture has inched up another 10 percentage points.

This year's Values and Beliefs poll, conducted May 1-10, also shows 67% of Americans in favor of same-sex marriages being legal -- a new high for that viewpoint. Separately, Gallup recently reported that the percentage of Americans identifying as lesbian, gay, bisexual or transgender has increased a full point since 2012 and is now 4.5%.

The perception that a person is born gay rather than it being the result of upbringing or other factors has increased among all demographic and political groups. But, according to a comparison of aggregated data from 2001 to 2003 vs. 2015 to 2018, the change in beliefs has been most pronounced among politically left-leaning groups, including young adults (aged 18 to 34), college graduates, Democrats, liberals and those who seldom or never attend weekly religious services.

	2001-2003	2015-2018	Change
	%	%	pct. pts.
Men	33	43	+10
Women	45	54	+9
18-34	35	52	+17
35-54	41	46	+5
55+	41	49	+8
College graduates	46	58	+12
College nongraduates	37	45	+8
Republicans	30	36	+6
Independents	40	50	+10
Democrats	47	61	+14
Conservatives	29	33	+4
Moderates	46	51	+5
Liberals	50	71	+21
Weekly church attendance	29	34	+5
Nearly weekly	38	43	+5
Seldom/Never	48	59	+11
Gallup

The groups showing the biggest increases in adherence to the "nature" explanation are, for the most part, those who tend to be more inclined toward this view to begin with. One exception is young adults -- in the early 2000s, they were a bit less likely than older adults to hold this view, but they have since become the most likely of all age groups.

Despite the increases, support for the nature position remains low among Republicans (36%), conservatives (34%) and weekly churchgoers (36%).

Perceived Origin of Sexual Orientation Influences Gay Rights Views

The nature vs. nurture argument about the origins of sexual orientation has been an integral part of the gay rights debate over the years, and it is clear why. Americans who believe gays and lesbians are born with their sexual orientation are much more supportive of gay rights than are those who say orientation is due to upbringing and environment.

This is seen clearly in the latest polling in terms of support for gay marriage. The vast majority (88%) of those who think being gay or lesbian is present at birth believe same-sex marriages should be legal. By contrast, the majority of those who think it is due to upbringing (61%) think these marriages should not be legal.

Notably, among the 10% saying both factors contribute to being gay, a solid majority (67%) believe same-sex marriages should be recognized by the law as valid.

	People are born gay or lesbian	Result of upbringing/environment	Both
	%	%	%
Same-sex marriages should legally be valid	88	38	67
Same-sex marriages should not be valid	11	61	27
No opinion	1	1	6
Gallup, May 1-10, 2018

Bottom Line

Americans have gradually moved toward the belief that being gay or lesbian is not "caused" by upbringing and environmental factors, but rather is a trait a person is born with. While this is not a universal view, a solid 60% ascribe some role to nature when factoring in those who think both nature and nurture are involved.

This could have important implications for public support for gay rights, as those who believe nature has a hand in sexual orientation are much more likely to be sympathetic to affording gays equal rights in marriage. It's not clear if the two views merely go hand in hand, or whether views on the explanation for being gay or lesbian drive attitudes about gay rights. To the extent it's the latter, as Americans increasingly adopt the "nature" explanation for sexual orientation, support for gay rights could also grow.