Av. = -1.92 P. E. M. = -2.54 P. E. Similarly, it might be thought that the children who had suffered from the defects for a comparatively short time, might reveal greater improvement in intelligence after six months than those who had been afflicted for a longer space of time. We had no way of knowing definitely how long the defects had been present in the cases studied. Roughly, though, we may say that in general the older boys have had defective tonsils and adenoids for a longer time than the younger ones, and that the older the boy, the older the defect. On this basis, if correlation of youth with gain in I.Q. should give a larger positive value for r, we might be justified in saying that the younger boys, who have been handicapped for a lesser period, show greater mental recuperation than their older companions. Such a correlation was attempted in the test group, correlating age at the first test with gain in I.Q. The same methods and formulae were used as in the weight and intelligence comparison, the greatest gain in I.Q. being given first position, and the lowest age. The resulting value for r was -.24, with an unreliability of .186. The relationship would appear to be in the other direction but it is so small, with an unreliability measure so large as to be insignificant. Once more, then, we find in our results no correspondence between recency of defect and quick mental recovery. TABLE XI Showing percentile ratings of the members of the two groups at the beginning and end of the six months' interval Weight Height Grip Tapping 1 .29 .44 .25 .40 .47 .40 .51 .33 1C .43 .54 .27 .45 .33 .47 .17 .30 2 .04 .10 .04 .11 .16 .16 .16 .25 2C .38 .55 .20 .32 .25 .40 .80 .28 3 .46 .59 .32 .49 .44 .56 .52 .58 3C .65 .69 .74 .81 .54 .67 .51 .42 4 .33 .44 .39 .52 .16 .13 4C .27 .32 .51 .78 .18 .19 5 .16 .20 .18 .20 .33 .23 5C .50 .53 .28 .47 .40 .87 6 .12 .15 .06 .10 .10 .23 6C .31 .40 .22 .38 .27 .41 7 .03 .07 .05 .15 .07 .06 .40 .27 7C .01 .02 .03 .07 .16 .24 .16 8 .62 .71 .63 .75 .24 .27 .23 8C .18 .37 .31 .40 .67 .72 .43 .11 9 .31 .41 .47 .53 .26 .47 .71 .51 9C .60 .65 .76 .89 .76 .89 .63 .78 10 .26 .35 .26 .43 .44 .33 .01 .04 10C .21 .22 .23 .37 .24 .67 .02 .51 11 .24 .23 .25 .43 .33 .67 .40 .08 11C .08 .09 .09 .17 .36 .36 .86 .11 12 .25 .40 .15 .53 .08 12C .06 .15 .02 .08 .04 .01 .12 .03 13 .95 1.00 .99 1.00 .99 1.00 .90 .66 13C .87 .89 .93 .96 .94 .96 .78 .36