The average gain of the test group was 309 points after 12 months, compared with 225 after six. The control group, however, made an average gain of 624 after 12 months, the gain after six months being 329. These numbers are insignificant as gains, but they at least show no improvement in the test group which the control group does not reveal as well. On the basis of the results, we may say that there has been no improvement in I.Q. as a result of operation, either after six months or after twelve.

There remains to be considered only the result of the Healy Picture Completion Test. We have scores in this test for 18 pairs of cases. When these scores are compared with those in the former tests, the results stand as follows:

Average of gains of test group in excess of control -585 -336 Median of gains of test group in excess of control -775 1 P. E. of difference 305 338 Average in terms of P. E. -192 -87 Median in terms of P. E. -254 26

The figures given above show no gain in the Healy test as a result of operation. Both after six months, and after twelve, we find that the test group has gained no more than the control group. As before there are individual cases showing considerable gain in the second period, but these are matched by control cases which reveal equal or even greater gains. In the test group, 5 cases lost in the second period in comparison with the first, 18 gained, and 7 gained as much in the second period as in the first. The control group lost in the second period in 5 cases, gained in 18, and gained as much as in the first period in 7 cases. The two groups, then, are practically equal, both showing a gain in the second period, but this gain cannot be due to the operations, since the control group did not undergo operation.

CHAPTER V.

SUMMARY.

The results obtained from the experiment may be summarized as follows:

1. Six months after operation for adenoids and tonsils, there seems to be a slight but not very reliable gain in weight as the result of the operation. After twelve months this has increased; indeed, it has very nearly doubled.

2. Gain in height, resulting from operation, is so slight as to be unreliable. This gain does not increase during a second period of six months.

3. The height-weight-age relationship is an excellent measure of the physical well-being of the child. The figures expressing this relationship show no very reliable gain in the first six months, but improvement increases considerably during the second period.

4. The test group shows no gain over the control group in strength of grip. There seems on the other hand to be a slight loss; which does not decrease in amount during the second period.

5. Speed of tapping did not increase during the first period, any more for the test group than for the control. During the second period, however, there is a marked improvement.

6. Operation for adenoids and tonsils does not lessen fatigueability as shown by the tapping test. The probability is, however, that the test is at fault.

7. No rise in I.Q., as a result of operation, makes itself evident after six months or after twelve months.

8. There is no improvement in the performance of the Healy test either after six months or after twelve.

9. In every test except grip and tapping, there is a marked increase in the variability of the gains after the second period. This is possibly due simply to the fact that the longer interval permits the intervention of more extraneous factors which may influence the scores in one direction or the other.

10. A group of 236 children with diseased tonsils showed equal distribution of I.Q. with a group of 294 children who were normal in this respect.

CONCLUSIONS

The article by MacPhail, which has been reviewed in a former chapter, showed pretty conclusively that the removal of adenoids and tonsils was followed by improvement in school work. That such improvement was not due to a rise in general intelligence can be concluded from the present experiment. That efficiency in school work does not rest wholly upon intelligence has been demonstrated more than once. The tendency here noted to improve in general physical tone may, perhaps, serve as a sign of the factor upon which such improvement depends. Improved health means better attention, better emotional response, greater resistance to fatigue, and probably increased efficiency.

Interesting investigations of such improvement in efficiency might be made by administering educational tests to groups similar to those of the present study. The results of such an experiment would be exceedingly instructive, and would be more significant than conclusions drawn from school marks. By this means also we might determine along what special line efficiency is most affected.

Since there was no recuperation in intelligence resulting from operation for adenoids and tonsils, it is reasonable to expect that there had been no r.e.t.a.r.dation from which to recuperate. This supposition is borne out by results of the statistical study, wherein we found that a group of children suffering from diseased tonsils possessed equal intelligence with a group which was free from such defect.

We can say to physicians, then, with fair amount of a.s.surance, that removal of adenoids and tonsils will probably not raise to any great degree the intelligence level of the mentally defective child who is brought to him. We can say to students of the constancy of the I.Q., that it is not greatly lowered by adenoids and diseased tonsils and we may say to the clinical psychologist that these defects have no demonstrable effect upon general intelligence, whatever effects they may have on volitional and emotional normality,--the two elements which, along with intelligence are necessary for the maintenance of the individual as an instrument of social efficiency.