The Gerontology Research Group validates current longevity records by modern standards, and maintains a list of supercentenarians. Record-holding individuals include: Jeanne Calment (1875–1997, 122 years, 164 days): the oldest person in history whose age has been verified by modern documentation; Shigechiyo Izumi (1865–1986, 120 years, 237 days, disputed): the second oldest male ever recognized by the Guinness Book of World Records; this is questioned by some scholars, who believe that conflation of dates or names has compromised the authenticity of Izumi's age. __