A growing majority of Americans say athletes should compete on men's or women's sports teams that correspond to their biological sex rather than their gender identity, according to a June 12 Gallup poll.

The new poll found that 69% of U.S. adults said athletes who identify as transgender should only be allowed to compete on sports teams that match their biological sex. The findings represent an increase from a 2021 Gallup poll, when 62% of U.S. adults said the same.

Likewise, just 26% said athletes should be able to compete on men's and women's teams that conform to their own gender identity, instead of their biological sex. This is down from 34% in 2021.

The findings come as more Americans report knowing someone who identifies as transgender. The same Gallup poll found 39% of Americans said someone they know personally has told them they are transgender, up from 31% in 2021.

Supporters of prohibitions on athletes who identify as transgender from competing on teams opposite their biological sex argue it would adversely affect women's sports by allowing biological male competitors who may have an advantage over them in factors including weight and size. But opponents argue such prohibitions are unfair to athletes who identify with a gender that is not congruent with their biological sex.

The shift in American public opinion comes as the issue has become increasingly controversial. So far 22 U.S. have enacted laws to ban transgender athletes who are biologically male from competing against female athletes, according to data from the Movement Advancement Project, an LGBTQ+ policy group.

In a blog post accompanying the poll, Gallup senior editor Jeffrey M. Jones wrote the data appears to show that "Americans view transgender sports participation more through a lens of competitive fairness than transgender civil rights."

"Even Democrats, who mostly support LGBTQ+ rights and affirm the morality of gender change, are divided on the issue of whether transgender athletes should be allowed to participate on teams that match their gender identity rather than birth gender," Jones wrote.

In guidance on health care policy and practices released March 20, the U.S. Conference of Catholic Bishops' Committee on Doctrine said it opposed surgical or hormonal interventions that "aim to exchange the sex characteristics of a patient's body for those of the opposite sex or for simulations thereof."

"Any technological intervention that does not accord with the fundamental order of the human person as a unity of body and soul, including the sexual difference inscribed in the body, ultimately does not help but, rather, harms the human person," the document states.

On this point, Gallup also found a majority of Americans held similar moral views as the U.S. bishops. Approximately 55% stated "changing one's gender" to be "morally wrong," while 43% said it is "morally acceptable." Back in 2021, Gallup noted 51% said changing one's gender was morally wrong versus 46% who found it morally acceptable.

There is no clear data on how many athletes -- students or otherwise -- who identify as transgender compete on teams opposite their biological sex in the U.S., as many sports associations do not track those numbers.

A 2022 study by the UCLA Williams Institute found approximately 1.6 million people in the U.S. age 13 and older who identify as transgender.