Father of the word "Ageism" ,Dr. Robert Butler, passed away in New York City at 83.
Dr Butler's daughter Christine said that he died of leukemia at Mount Sinai Medical Center, reports the Telegraph.
A gerontologist and psychiatrist, he was the founding director of the National Institute on Aging, one of the National Institutes of Health.
This research helped to set the agenda for concepts as "productive aging" and "successful aging."
He also is credited with the concept known as "life review," a therapeutic device people can use to reflect on their lives, said Ev Dennis, secretary of the longevity centre board.
Butler also wrote several books on aging, including the 1976 Pulitzer-winning 'Why Survive: Being Old in America'.