For researchers studying aging — and thinking about how to extend our lives — a key question has been how much our genes shape our lifespans. AdvertisementWhile scientists have identified some genes that affect lifespan, the studies suggested that it was our environment that really carried the day in determining how long we lived. Scientists have seen roughly that level of lifespan heritability with other species, as well as with other human traits, such as psychological factors like introversion. You have effectively changed the trait from overall lifespan to lifespan under a specific set of conditions. In addition to boosting the case for genetic research into aging, the new study’s implication that our DNA is more important to longevity than thought also supports the notion that genetic information could help inform people’s plans about their lives.