Average age at death: A ?awed statistic summarizing expectancy of the life and other aspects of the mortality. For instance, a study comparing average age at the death for male symphony orchestra conductors and for the entire US male inhabitants showed that, on an average, the conductors lived almost four years longer. The difference is illusory, cause as age at entry was birth, and those in the US male population who died in the infancy and childhood were included in the calculation of the average life span of a person, whereas only men who survived to become conductors could enter the conductor cohort. The apparent difference in the longevity disappeared after accounting for the infant and perinatal mortality.