6 
A Study in Criinmal Anthropometry 
and normal criminal be solely an age difference? An examination of Table B 
shows that the mean age of the weak-minded is 38-16 years and of the normal- 
minded 44-86 years, or the former are younger by 6-70 years. This would correspond 
only to an average greater temperature of -034 degrees as against the observed 
difference of -164 degrees. The temperature difference of weak- and normal-minded 
is therefore not due to age difference. This is confirmed in Diagram II, where 
the observations and the calculated regression lines for the weak-minded and the 
normal-minded groups* are plotted alongside each other. Notwithstanding the 
irregularities due to the smallness of the sample, it will be seen that at every age 
the mentally defective have a higher temperature than the normal-minded, and 
further that, as averaged out by the regression lines, the difference at each age is 
sensibly constant (the regression lines are practically parallel) and equal to 0°-2. 
We conclude that weak-minded adults have a higher temperature than normal- 
minded adults and in this respect differ from mentally defective children who are 
* The equation to the regression line of the weak-minded group is jr = 98-6535 — ■002796^4, and 
of the normal-minded group ^ = 98-5063 --003939^. 
