30 might just feel little bit like 72 for this girl…
Under the headline “Modern humans found to be fittest ever at survival, by far” Los Angeles Times recently featured an article about a study from the Max Planck Institute for Demographic Research, on the increase in life expectancy,
A typical Swede, for instance, is more than 100 times more likely to survive to the age 15 than a typical hunter-gatherer. And a hunter-gatherer who has reached the ripe old age of 30 is about as likely to die in the following year as the world’s champion of longevity — a 72-year-old woman in Japan.
But are Swedes and the Japanese really representative of all modern humans, or even of populations in the developed countries? I think it’s safe to say that these two people are known to have certain traits, national characters, that set them apart. Hardly anyone would argue with the claim that they are less impulsive than the average.
Research on national characters – the specific collective personality traits that distinguish on nationality from another – has proven difficult. A large study by Terracciano back in 2005 found that the national characters don’t accord with mean levels of personality traits. So is this idea just in our heads, that say the Chinese are more introverted than Americans?
Most likely not, since all research into stereotypes so far tends to find a kernel of truth in them – Jews as a group make more money, African Americans as a group are more violent etc. But personality research is almost exclusively done with self-report questionnaires. When people answer question about their own personality they relate it to other people in their own country. This means that differences between countries can be due to other factors like how socially desirable a trait is in that country or how prone a certain people are to self-enhancement, portraying themselves as better than they are. Studies have found that East Asians are not as prone to this as Westerners which could explain why Americans for instance measure higher than the Japanese on conscientiousness.
Some psychologists have tried to get around this problem by looking at how personality traits are expressed in different cultures, or to use ethos in the form of institutions that embody ideals that are typical of certain traits. But that’s all very problematic since it involves measuring the same thing in different and indirect ways.
A better way to do this (which at least I haven’t read about) is to measure actual behavior related to personality traits. Because there are traits that have universal behavioral outcomes. Take impulsivity for instance. This trait predicts drug abuse, violent crime, traffic accidents etc in all parts of the developed world. So if these outcomes differ according to stereotypical notions of national characters then we have some evidence that these do reflect actual personality differences between nations.
Since I haven’t come across any such research I decided to dabble a little myself, just to see if there might be anything to this. I took two measures – adult lifetime use of cannabis, and road fatalities – and combined them into a composite measure of impulsivity. The countries included are mainly those commonly thought of as impulsive, New Zealand, USA, Australia, and Denmark. I contrasted these against the two nationalities mentioned in the article, those of Sweden and Japan. So here is what I found.
Adult lifetime use of cannabis according to Wikipedia/EMCDDA: Stereotypically impulsive nations like USA 42.4 percent, New Zealand 41.9 percent , Denmark 36.5 percent, and Australia 33.5 percent. As a contrast Sweden has 12 percent and Japan a mere 1.5 percent.
Road fatalities per 100K inhabitants and year according to Wikipedia/WHO: Again looking at the stereotypically impulsive nations we have, Australia 5.7, New Zealand 8.6, USA 12.3, Denmark 7.4, whereas Sweden has 2.9 and Japan 3.85.
If we combine these percentages to a composite measure of impulsivity by adjusting so both measures have the same average, we find the following order with life expectancy in the second column,
USA 50 78.2
Australia 56 81.2
New Zealand 77 80.2
Denmark 67 78.3
Sweden 24 80.9
Japan 17 82.7
This gives us a clear indication that nations thought of as impulsive actually have more outcomes that are known to correlate with impulsivity on the individual level. Their average level is 62.5, which is 3 times the average of Japan and Sweden combined. It’s especially striking to see the big difference between the neighbors Denmark and Sweden that are very similar in many other ways. And this measure of impulsivity also correlates -0.6 to life expectancy which is quite respectable.
…but not for this one.
Although it’s not a scientific study, I believe this little exercise clearly raises the question of whether any developed country can be taken as a measure of how technological progress translates to longer life expectancies in general. It suggest that this is not the case, and that differences in personality traits between countries, often referred to as national characters are in fact real, and affect health and longevity in the same way as they do on the individual level.