At the World Congress of Gerontology and Geriatrics in Paris, amid sessions on Alzheimer’s disease, elderly care, and osteoporosis is a session provocatively titled «Ageing Is No Longer an Unsolved Biological Problem.» It’s organized by Leonard Hayflick, a professor of anatomy at the University of California, San Francisco. Hayflick spoke with Technology Review about his theory for the biological causes of aging and explains why he thinks that research directed at the fundamental processes of aging will yield greater returns than studying diseases of aging, such as Alzheimer’s and cardiovascular disease.