I have looked into homicide rate and IQ data for countries. My sources are:
Therefore more countries in Homicide Rate sources, therefore I needed to chop the ones which did not have IQ average data. In total, there are 180 countries in the comparison.
Correlation is -0.38. This means the higher the IQ the lower the homicide rate, and therefore your chances of being murdered in that country.
We can further play with the data, doing some averaging to get visually nicer and understandable picture.
Every 5 points average: Correlation:-0.68
Every 10 points average: Correlation:-0.79
Every 20 points average: Correlation:-0.90
Every 30 points average: Correlation:-0.90
Of course the correlation will increase with averaging. But this is only to give a clearer picture.
There is another possibility of looking at the data, from correlation point of view, analysing the data from part to part. The following figure shows the correlation (IQ vs homicide rate) vs average IQ. This will give us information about the correlation until that particular IQ average point. This is done in order to explain the bump around IQ average 80.
Picture above show how the correlation change with additional data. This will give information about the nature of IQ vs homicide rate correlation. The interesting observation is that, after the average IQ of 80, the negative correlation gains momentum increasing until -0.38. Until IQ average 80, there is almost no or very weak correlation between IQ vs homicide rate for countries. Initial couple of points show strong correlation however, these are too few data to conclude on that initial correlation.
From these pictures, we can conclude that until the average of IQ 80, the homicide rate has very weak correlation with average IQ of a country. Above 80 IQ, the correaltion gets stronger on negative side with increasing IQ. And it stabilizes around IQ average 100.
In any country below IQ average of 80, your chances of being murdered is on average 7 times higher than a highly developed/high IQ (mostly european) country.