If aging is an increase in the probability of death, then as we as a society figure out how to delay death, we age more slowly. In the Stone Age, people were beset by environmental hazards and subject to accidents and death by violence. Today those causes are less common. Instead, age-related diseases (ARD) limit lifespans.
If aging is an increase in the probability of death we age slower today than we did in the Stone Age because the probability of death from environmental hazards is lower. And if we want to slow aging, we should do what we can to reduce the probability of death.
The Census Bureau projects Americans’ life expectancy will increase by six years to 85.6 in 2060.