Final answer:
The claim is false; Millennials have been found to be more socially liberal and tolerant of diversity than older generations, such as Baby Boomers, who did engage in social reform but did not display the same level of liberalism as later generations.
Step-by-step explanation:
The statement that research on the so-called "Millennials" shows them to be significantly less tolerant of diversity than the Baby Boom generation that experienced the 1960s is False. Over time, the United States has become more socially liberal, especially on topics related to race and gender. Millennials, who were born between 1981 and 1996, are generally more liberal than members of older generations. The Baby Boomers, born between 1946 and 1964, did engage in social reform, contributing to civil rights and anti-war movements, but on the whole, generational progress has seen an increased openness and tolerance in younger generations, including Millennials.