Do We Live Longer Than The Romans?
It seems like an easy question to answer, and in a sense, it is: on average, people today live significantly longer than our ancestors.
In the last century, global average life expectancy has more than doubled. However, life expectancy doen't tell the whole story.
It is easy to assume that advances in medical science have pushed the boundries of human lifespan, allowing us to live longer than ever before.
A Roman, one assumes, would therefore be awestruck by anyone living over the age of 60, while living to 100 would surely be unthinkable.
However, this is likely to be far from the truth. Most of the boost in life expectancy we have enjoyed has nothing to do with an increase in maximum human lifespan.
Rather, we are simply far less likely to be killed before we reach the age limit that biology has set for us.
It is often estimated that the Romans and Greeks lived to an average age of just 35.
However, this number does not mean much in terms of what would have been considered 'old'.
If 1/2 Romans died before their first birthday, but those who survived lived to 70, this would produce an average life expectancy of 35.
This does not mean that living to 70 would be seen as unattainable, or that and age of 35 would be considered old.
Indeed, the roman author and naturalist Pliny (who himself lived to the age of 56) wrote in The Natural History of multiple individuals who lived to 100 and beyond.
So what would actually have been considered 'old' by the Greeks and Romans?
Before 100BC, Greeks and Romans who did not die violently or in childhood had a median recorded age of 72.
While this data has obvious limitations, it is supported by more detailed records kept by later civilisations.
Between 1200 and 1745, those who made it to the age of 21 would reach an average age of anywhere between 62 and 70.
Furthermore, life expectancy in modern hunter-gatherer groups averages in the 30s, but those who survive adolescence often live to their 50s or 60s.
This suggests that even the lives of pre-historic humans may not have as short as one would assume.
The takehome message from all this? We owe our unprecedented life expectancy to the fact that more people are reaching their maximum lifespan.
However, there is no concrete evidence that maximum lifespan has increased by much.
We may soon reach a point at which life expectancy can no longer be significanly increased due to a 'ceiling' of maximum lifespan.
Once this point is reached, new kinds of advances - that is to say, the means to slow the process of biological ageing itself - may be required to further improve human life expectancy.