IQ2^. Xc. -L. PHYSICAL DEVELOP^ÎEINT '7 CHIirRTN .'.vr> VOVNO PEOPLE. IQ 



(anyway from lo) to 12 — j ? years, then a decrease ^*. We shall pre- 

 liminar}- state this fact and abstain from any commentary, f. inst. the 

 possible connection of the development of pubert}' of the two sexes, be- 

 fore we have a collected view over all anthropometrical results and 

 ftirthermore can compare these with the photographs. 



The grow^ from year to year. 



The public school material is here easy to make use of, as the 

 probable error is so very small. \\'ith the higher school we start from 

 the rounded off values (table i) marked on millimeter paper after the 

 most natural curve construction and compute from this the growth from 

 year to year in centimeter. Curves are not constructed after these results, 

 as — which has been repeatedly stated in my earlier writings — the laws 



Fig. 7 a. Fig. 7 b. 



of growth cannot be reliably studied after such absolute numbers. We 

 therefore compute a grozi'th-coefficienty the growth in percentage, how 

 much the children grow on an average from year to year — the centi- 

 meter-increase in percentage of the starting point value. Example: — 

 From 8 years (average height T21.8 cm.) till 9 years (126.1) the public 

 school boys grow 4.3 cm. = 3.5 /c of the 8 year olds height. Hereby 

 we are getting a truthful expression for the really unfolded growth energ>- 



As will be seen from the perpendicular lines the probable error is not wholly 

 immaterial. The drawing of the curve (cf. fig. 6) was therefore performed in the 

 following manner, iUustrated by two examples: The value for 13 years old boys 

 (higher schools) is computed as average number of the arithmetical average values 

 for 12, 13, and 14. It falls in one place within the borders of error for 13 years 

 (inside the perpendicular line). -\ similar value for 18 years (the average value 

 of 17, 18, and 19 years) falls below the border of error for 18 and is marked 

 with a cross. For this age the curve is marked as near the mentioned cross as 

 possible, that is, at the ver>- bottom of the perpendicular line, in other words, at 

 the lowest border for the probable error. Hereby is avoided subjectivity and 

 arbitrariness at the drawing of curves, and a natiiral smoothness in the course is 

 secured. .\t the same time principal errors are escaped by everywhere keeping 

 within the mathematically computed probable error. 



