Crime and IQ in Finland

James Thompson summarizes an article on the IQs and criminal records of all 21,513 males born in Finland in 1987:

Joseph A. Schwartz, Jukka Savolainen, Mikko Aaltonen, Marko Merikukka, Reija Paananen, Mika Gisslerd. Intelligence and criminal behavior in a total birth cohort: An examination of functional form, dimensions of intelligence, and the nature of offending. Intelligence, Vol 51, July–August 2015, Pages 109–118.s

I’m guessing the X-axis is demarcated in 9 stanines, but I can never remember what stanines are. (They are half of a standard deviation.) If so, 1 would be 1.75 standard deviations or less below the mean (IQ of 74 or less) and 9 is 1.75 s.d. above the mean (IQ of 126 or more).