New York City ? Dr. Robert Butler, a Pulitzer Prize-winning expert on aging who coined the phrase “ageism,” has died in New York City, his daughter said Tuesday. He was 83.

He died Sunday of leukemia at Mount Sinai Medical Center, Christine Butler said.

Butler, a gerontologist and psychiatrist, was the founding director of the National Institute on Aging, one of the National Institutes of Health. He wrote several books on aging, including the 1976 Pulitzer-winning “Why Survive: Being Old in America.”

Butler coined the term “ageism,” or age discrimination, in 1968, and led a task force that analyzed the impact of age prejudice in a 2006 report, “Ageism in America.” It addressed age discrimination in the workplace, elder abuse and the media’s role in perpetrating such bias.