In Irish life-expectancy terms, it was a week in which statistics finally ran smack into stereotype. If you are male and turned 40 between 2009 and 2011, then at the moment your internal clock ticked into a new decade you were expected to live another 39.5 years, give or take an afternoon.
So if the morning of your birthday began with a breakfast of midlife angst, sprinkled with wasted youth, then congratulations: you were statistically justified. An Irish man creeping up on 40 really has reached the crest of the hill.
After that it is a backaching, nose-hair-sprouting slow roll to the bottom. Although, more accurately, there would have been a day somewhere towards the final weeks of his 30s when the Irish male would have been allowed a howl of crisis – ideally not while driving the kids to GAA.
That projection was contained within the Central Statistics Office's Population and Labour Force Projections 2016-2046 , which was at pains to stress that it was not making hard-and-fast predictions about the future population but indicating a range of possible outcomes (none of which, disappointingly, mentioned space travel). And, likewise, the stats around life expectancy are not nearly as neat as allowing you to predict what day a man should wake up and impulse-buy a sports car.
Life expectancy is one of the great metrics of a society, yet it comes with caveats and footnotes and competing methodologies. Still, as the decades roll on, and the graphs get longer, the statistical byways remain irresistible.
In an Irish context, we see that within the overall climb in life expectancy – in 2010 it was 77.9 years for a man, 82.7 years for a woman – are some alarming gorges. Most obviously, as estimated by the All Ireland Traveller Health Study , is how the life expectancy for male Travellers is the same as it was for the general population back in the 1940s (61.7 years), and for women it is the equivalent of the general population in the 1960s (70.1).
Those stats have their equivalents in many other countries. This month, for instance, it was estimated that, in New Zealand, Maori men and women drop short of the non-Maori population’s life expectancy by eight years.
Single Limerick male
Educational opportunities, address and societal status, then, remain major factors in how long a person is expected to live. Again in 2010, official figures led to reports that the lowest life expectancy would be found in a male living alone in a council house in Limerick.
That conclusion was based on a selection of figures, such as that married men live longer than single men, urban dwellers die before rural ones, and homeowners live longer than those in rented accommodation.
You could spend all day putting such demographics in ever more complex combinations, and there are people who spend happy hours at work doing just that, and even then surprises will ambush them from the darker corner of a Venn diagram.
In New York it has been claimed that the falling murder rate is 2 per cent responsible for the rise in general life expectancy. In addition, better treatment means that improved life expectancy for people with HIV/Aids is credited as being 11 per cent responsible for the rise in the general population.
Yet in rural counties of New York, as in other parts of the US, there is concern that life expectancy for white women is declining in such a way that they will be the first in several generations to live shorter lives than their parents.
Several factors have been identified – obesity, poverty, diet, environment – but this blip in the chart is something of a demographic mystery. Perhaps there is a clue in a recent major Dutch study, which concluded that the people of this generation are more “metabolically” unhealthy than their parents and grandparents; even if they are living longer, their bodies are less able for it.
And so on, stat infinitum. After which it’s down to the quantum level of a person’s own expectations and understanding. A 1980s study in the US, though likely outdated, still gives a good insight into the psychology of expectations about life expectancy.
It found that white male smokers expected to live four years fewer than nonsmokers – bang on the actuarial estimate at the time – yet those who didn’t exercise expected to live the same length of time as those who did.
Those who had long-lived parents or grandparents believed they would live 12 to 18 years longer than those with short-lived ones, an estimate greatly in excess of reality.
In other words you are not only as old as you feel but also as old as you feel you’ll be. Except, of course, if you’re Irish, male and have just turned 40. You’re done for. Sorry about that. Blame science.
shegarty@irishtimes.com
@shanehegarty