"The Economist" observed in 2013 that, like their British counterparts, millennials in the United States held more positive attitudes towards recognizing same-sex marriage than older demographic cohorts. However, a 2018 poll conducted by Harris on behalf of the LGBT advocacy group GLAAD found that despite being frequently described as the most tolerant segment of society, people aged 18 to 34—most Millennials and the oldest members of Generation Z—have become less accepting LGBT individuals compared to previous years. In 2016, 63% of Americans in that age group said they felt comfortable interacting with members of the LGBT community; that number dropped to 53% in 2017 and then to 45% in 2018. On top of that, more people reported discomfort learning that a family member was LGBT (from 29% in 2017 to 36% in 2018), having a child learning LGBT history (30% to 39%), or having an LGBT doctor (27% to 34%). Harris found that young women were driving this development; their overall comfort levels dived from 64% in 2017 to 52% in 2018. In general, the fall of comfort levels was the steepest among people aged 18 to 34 between 2016 and 2018. (Seniors aged 72 or above became more tolerant of LGBT doctors or having their (grand) children taking LGBT history lessons during the same period, albeit with a bump in discomfort levels in 2017.) Results from this Harris poll were released on the 50th anniversary of the riots that broke out in Stonewall Inn, New York City, in June 1969, thought to be the start of the LGBT rights movement. At that time, homosexuality was considered a mental illness or a crime in many U.S. states.