A new study says that young people have become increasingly less interested in the environment and conservation issues over the last four decades. In an analysis of two longstanding surveys of U.S. high school seniors and college freshmen, researchers found that today’s generation of so-called Millennials are less likely to be concerned with the government or think about social problems, particularly related to environmental issues. According to their findings, published in the Journal of Personality and Social Psychology, only 21 percent of young people today say they find it important to become personally involved in efforts to clean up the environment, compared with about 33 percent of younger Baby Boomers and about 25 percent of Generation Xers, the group of Americans born between the early 1960s and the early 1980s. About 15 percent of Millennials said they had made no effort to help the environment, compared with 5 percent of young Boomers and 8 percent of Gen Xers. “We have the perception that we’re getting through to people. But at least compared to previous eras, we’re not,” said Jean Twenge, a psychology professor at San Diego State University and an author of the study.