Statistics :( Just add another variable - officer or soldier - and the conclusion can be reversed. Clearly no causation here: higher percentage of officers died, and officers were smarter.
I was about to make the same comment and also point out that even int the most un-brainy situations brains help.
I recall a study that showed higher IQ toddlers are less likely to die in an accident. Even in our super child safe words, even with toddlers, brains go a long way.
But then again higher IQ might correlate with higher family income which correlates with more parental attention... that's statistics for you.
Even within income groups, intelligence and the ability to save (and invest) some of your earnings might be correlated. In that case, smarter people would lose more when the market tanks.
Higher IQ toddlers are likely to have higher IQ parents who may be less likely to leave them unattended at the swimming pool, to have dangerous objects around the house, etc.
But there were at least 10 times more soldiers than officers. That means officer's death risk was at least 3 times higher than soldier's. They also mention that average IQ of a soldier that died was 95.
As someone who doesn't know much about military strategy, I find it surprising that officers are more likely to die in combat (or were in WWII, at least). Isn't it enlisted guys who ride at the tip of a dangerous advance?
Most officers in WW2, certainly in Britain, were enlisted rather than career officers. This particularly applies to the lower ranks of officer, such as captain and lieutenant.
Leading from the front was common, for officers up to the rank of General, because it was the best way of knowing what was going on. There was no "blue force tracker" in those days!)
But Sergeants and Corporals are non-commissioned officers, and they are fighting in the muck with the rest of the enlisted soldiers.
If you consider the size of the average squad led by these non-coms (certainly larger than 5 people), then 20% of deaths is still probably not too good, but from what I know these people don't lead from behind.
Officers made up 7%. A non-commissioned officer is simply an enlisted person that has stayed in service long enough to be promoted. Commitment is in no way indicative of intelligence. In some cases it's the opposite.
In a sample size of <500, assuming a standard deviation of 15 for the IQ test (since that's the most common) 3 points wouldn't seem to mean anything. Even a well-versed psychologist wouldn't be able to reliably tell apart people with a difference if .2 standard deviations.
I am not so used to statistics anymore (in fact probably never was). I just wonder if there isn't a difference between comparing the IQ of two people (5 points difference maybe not significant) and comparing the average IQs of two "large" groups of people - since the average was 95, it means that there were also some with an IQ of 80 and some with an IQ of 120 or whatever. Meaning a difference of 5 point in the averages might be more significant than a difference of 5 points between two people?
As I said, I am not used to these calculations anymore, and it is too late at night now to do the research... Maybe tomorrow... Or maybe you can answer that question (guessing that years of playing poker make you quite experienced in such things...).
You are correct. I'm not sure exactly, but I suspect that it would be entirely within the realm of reasonable possibility for two equal groups of 250 to end up 5 points apart with an SD of 15. You could find out pretty easily with a script and a Gaussian RNG function if you were so inclined. My curiosity on this one is just slightly overpowered by my laziness though.
But at the end of the day, where the line was drawn between significant and not was arbitrary and has no special meaning. The standardization around p values helps us to compare studies, sure, but it is not magical.
It is true that "significance" can be arbitrarily defined, but I think if you can calculate the confidence, it is not arbitrary. If you have the number that with x% probability something is the case, you have learned something.
I suspect that 490 is quite a big sample actually, but I am too lazy to do the maths (and I am missing background information - of course if it was just one battle, it is a different thing than looking at the whole of WW2, and so on).
Even the 3 IQ points I am not sure about - it might on depend where on the curve the difference appears. 30 points is a very big difference apparently (IQ 100 makes you smart enough for high school, and IQ 130 makes you smart enough for the Mensa club of highly intelligent people, or something like that). The 3 is not "3% difference in intelligence". I am not familiar enough with the whole IQ thing to be able to judge if the difference is significant, though.
Lately I have wondered about the "arms race" as Susan Blackmore calls it, between the gene and the meme. The genes want us to have small, efficient brains, capable of survival but not much else, whereas the meme wants us to have big brains because the bigger the brain, the more memes can get into it. This study, if confirmed, would seem to provide an interesting example of how bigger brains do not necessarily correspond to greater survival advantage. When viewed from the gene/meme perspective, this makes sense. The mortality associated with bigger brains is good for the gene, albeit bad for the meme, but not all that bad, because memes are not dependent on their host's surviving to make offspring. In short, memes don't care so much about our survival, only genes do. Genes, in turn, don't care so much about big brains, only memes do. Accordingly, that a bigger brain seems not to afford survival advantage in warfare is no surprise. When the war is finished, there will be plenty of smaller brain people out there left to continue to copy the gene. And as for the meme, as long as they were written down/persisted somewhere, they will get copied along too.
