Final answer:
Attitudes toward gay and lesbian relationships have become more positive over the years, as evidenced by increased approval of same-sex marriage and advancements in LGBTQ+ rights, yet discrimination and full acceptance issues still persist.
Step-by-step explanation:
In the context of gay and lesbian relationships, the statement that is true according to McCarthy as of 2018, is that attitudes toward gay and lesbian relationships have become more positive. This change in attitudes can be attributed to various factors, including media representation, increased interpersonal contact with gay and lesbian individuals, and legislative changes that advanced LGBTQ+ rights. For instance, less than 40 percent of American respondents approved of same-sex marriage in 2004, but by 2019, that percentage had grown to over 60 percent. Moreover, important political milestones such as the repeal of 'don't ask, don't tell' in 2011, the legalization of same-sex marriage by the Supreme Court in 2015, and the inclusion of sexual orientation and gender identity as protected categories against employment discrimination in 2020 have propelled this shift. However, it is critical to note that discrimination persists, and full acceptance is not universal, as same-sex marriage is legal in only a minority of countries and many LGBTQ+ people still face significant barriers.