Scientists who investigate the aging process and who do scientific studies of the biological, psychological, and sociological phenomena that are associated with old age and aging: "Some biogerontologists promote the idea that aging is a programmed phase of decline following the plateau of maturity."

"When biogerontologists attempt to take cells from organisms, whether plants or animals, and grow them in test tubes, old age soon overtakes the cultures and the cells stop dividing, and so the cultures die."