ered at the age of 16.
Thirteen is more than four times as fruitful of graduates as age 17;
fourteen bears a similar relationship to age 18; and the percentage for
fifteen is three times that for age 19, as is apparent from the above
figures. The fact that the decline of these percentages ceases at age
19 is probably due to the greater maturity of such later entrants.

When we make inquiry as to what portion of the graduates in each of the
above groups 'goes through' in four years or less, we get the series of
percentages indicated below.

PERCENTAGE OF THE GRADUATES WHO FINISH IN FOUR YEARS OR LESS,
FOR EACH OF THE ENTERING-AGE GROUPS

Ages 12 13 14 15 16 17 18

% of Each Group 84.3 85.7 75.8 79.5 84.3 80.4 100

It appears that the ones in the older age-groups who do graduate are
not so handicapped in reference to the time requirement for graduation
as we might have expected them to be from the facts of the preceding
pages. Perhaps that fact is partly accounted for by the not unusual
tendency to restrain the more rapid progress of the younger pupils or
to promote the older ones partly by age, so that by our school
procedure the younger and the brighter pupils may at times actually be
more retarded, according to mental age, than are the older and slower
ones.

Since the same teachers, the same schools, and the same administrative
policy were involved for the different entrance-age groups, the
prognostic value of the factor of age at entrance will seem to be
unimpaired, whether it operates independently as a gauge of rank in
mental ability, or conjointly with and indicative of the varying
influence on these pupils of other concomitant factors, such as the
difference of economic demands, the difference of social interests, the
difference in permanence of conflicting habits of the individual, or
the difference in effectiveness of the school's appeal as adapted for
the several ages. One may contend, and with some success, that the high
school regime is better adjusted to the younger pupils, with the
consequent result that they are more successful in its requirements.
The distractions of more numerous social interests may actually
accompany the later years of school age. In reference to the social
distractions of girls, Margaret Slattery says,[23] "This mania for
'going' seizes many of our girls just when they need rest and natural
pleasures, th