Identifying the correct length of life for long-lived individuals is highly important for the social and natural sciences, as well as for policymaking. The purposes of this paper are to propose a standardized age verification procedure and to report on the age verification case of Jiroemon Kimura (J.K.), who is assumed to be the longest lived man in the world. We propose two verification processes that we have named face validity and concurrent validity of age verification.
We collected official documents, and non-official records to check face validity. We also gathered life episodes told by J.K. and historical records to evaluate concurrent validity. Although we found several date inconsistencies among documents and mismatches between told episodes and actual dates of events, no critical discordances were discovered. In conclusion, we could verify that J.K. was born on April 19, 1897 and passed away on June 12, 2013 at the age of 116 years and 54 days.