The physical basis of precocity and dullness / W. Townsend Porter.

  • Porter, William Townsend, 1862-1949.
Date:
[1893]
Catalogue details

Licence: Public Domain Mark

Credit: The physical basis of precocity and dullness / W. Townsend Porter. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    When these tables are examined it is seen that in each age the mean weight of pupils in the higher grades is greater than the mean weight of all pupils at that age and exceeds still more the mean weight of pupils in the lower grades.* This fact is more conspicuous when the grade weights in Tables No. 2 andNo. 3 are expressed graphically. The curves thus secured are reproduced in Plato I. The mean weight of all pupils at each age is marked on the curve by a small perpendicular line near the figure indicating the age. The abnormal deviation of the ends of some of the curves from the general slope of the curve is due to the number of obser- vations at these points being too small for trustworthy results. The truth which the curves in Plate 1 express is very plain. They declare in unmistakable lines that precocious children are heavier and dull children lighter than the mean child of the same age. They establish a physical basis of precocity and dullness. Whether means or averages arc the more trustworthy tools in investigations of this sort is a matter of opinion. So long as their respective value is a subject of controversy investi- gators will accept no results as final which can be supported only l)y means. It must therefore be my first concern to show that the law: mean puecocity is related to mean phy- sical DEVELOPMENT may with equal truth be written: average precocity is KELATfi:D TO AVERAGE PHYSICAL DE- VELOPMENT. In Table No. 5 are found the average weights of boys dis- tributed by school grades, and the average weights irre- spective of grade. Pounds are in double-faced type and kilograms in “lower case” type. The number of observa- tions is in each case the same as in Table No. 2. * The eud weights of the series at same age are calculated from so smalt a number of observations that they sometimes vary from the law which the more numerous observations toward the middle of the series show to be true.