ourse, nothing in this situation to justify any deduction of the
sort that pupils entering at the age of 17 would have been more
successful had they been sent to high school earlier, except that had
they been able to enter high school earlier they would have represented
a different selection of ability by that fact alone. There is also a
sort of selection operative for the pupils entering at ages 18, 19, or
20, which tends to account at least partly for the rise in the
percentage of the non-failing for these years. It is safe to believe
that for the most part only the more able, ambitious, and purposeful
individuals are likely to display the energy required or to discern the
need of their entering high school when they have reached the age of 18
or later. The appeal of school athletics will in this case seem very
inadequate to explain their entrance so late, since the girls
predominate so strongly for these years. Then it may be contended
further that the added maturity and experience of those later entrants
may partly compensate for a lack of native ability, if such be the
case, and thereby result in a relatively high percentage of non-failing
pupils for this group.

It is readily conceded that the avoidance of failure in school work
serves as only one criterion for gauging the pupils' accomplishment. It
is accordingly important to inquire how the different age-groups of
school entrants compare with reference to the persistence and ability
which is represented by school graduation. A truly striking array of
percentages follows in reference to the question of how many of the
entering pupils in each age-group do graduate.

DISTRIBUTION OF THE PUPILS GRADUATING FOR EACH ENTERING-AGE GROUP

AGES
Totals 12 13 14 15 16 17 18 19 20

796 B. 14 115 290 253 99 20 2 1 2
1140 G. 5 151 465 363 121 26 5 1 0

% of Entrants 79.1 56.6 38.8 29.9 20.0 13.4 9.1 10.0 13.3

These percentages bear convincing testimony in support of the previous
evidence that the pupils of the earlier entering years are highly
selected in ability. Of all the high school entrants they are the 'most
fit,' the least likely to fail, and the most certain to graduate. The
percentage of pupils graduating who entered at the age of 12 is
approximately four times that of pupils who ent