[14]: In a few cases where the operation was postponed after the test had been given, the child and his control were retested just previous to the operation. Since both cases were retested, practice effect is of no great importance.

Six months after his first test, each child was retested, whenever possible. Since some children had dropped out of the groups for one reason or another, the final number in each group was twenty-eight. It was necessary to rearrange the control cases somewhat in order to fill in s.p.a.ces left vacant by those who were lost. In this rearrangement, the effort was made, 1. to pair cases whose ages were approximately the same; 2. to pair cases whose first tests were dated fairly close together. Since all the children were tested and retested under approximately the same conditions, this rearrangement will probably not greatly influence the results. The tests were always given in the same order.

The following table shows a list of the two groups, as originally paired, and as finally rearranged, with dates of tests and retests.

Dates of operation are given for the first group.

Test Case Original Control Final Control Test I Op. Test II Test I Test II Test I Test II

JB 10-15-19 10-20-19 lost SS 10-15-19 4-15-20 LL 10-15-19 10-20-19 4-15-20 LJ 10-15-19 lost SS 10-15-19 4-15-20 HK 10-30-19 11- 6-19 4-30-20 MG 10-21-19 4-30-20 MS 11-11-19 11-12-19 5-17-20 AA 11-20-19 5-17-20 GF 12-11-19 12-26-19 6-11-20 SD 12- 4-19 6-11-20 RJ 12-16-19 12-30-19 6-16-20 NF 12-10-19 5-14-20 JJ 12-16-19 12-30-19 6-16-20 ML 12- 5-19 6- 9-20 AG 1-15-20 1-16-20 7-15-20 LP 1-15-20 7-15-20 IK 2-14-20 2-16-20 8-11-20 AL 2-14-20 8- 2-20 HG 2-10-20 2-11-20 moved control removed AC 2-11-20 2-12-20 8- 2-20 JF 2-11-20 8- 3-20 CL 2-26-20 3- 1-20 8- 3-20 JF 2-26-20 8- 3-20 MR 2-26-20 3- 1-20 moved control removed SR 2-26-20 2-27-20 8- 3-20 PG 2-26-20 8- 3-20 IK 3-17-20 3-17-20 moved control removed AO 3- 8-20 3- 8-20 9-20-20 SK 3- 9-20 9-24-20 RB 3- 8-20 3- 8-20 moved control removed DT 3- 8-20 3- 8-20 mastoid control removed AL 3- 9-20 3- 9-20 moved control removed JD 3- 9-20 3- 9-20 9-23-20 DD 3-11-20 9-16-20 LS 3- 9-20 3- 9-20 9-25-20 KS 3-16-20 9-24-20 JB 3-12-20 3-12-20 moved control removed HS 3-13-20 3-13-20 9-21-20 MR 3-15-20 9-15-20 AM 3-13-20 3-13-20 9-20-20 JM 3-13-20 lost HH 4- 6-20 10- 1-20 SO 3-18-20 3-18-20 9-22-20 SS 3-22-20 wrong boy MA 3-23-20 9-23-20 IF 3-18-20 3-18-20 9-23-20 (adenoids PK 3-22-20 9-21-20 AD 3-19-20 3-19-20 9-20-20 LC 3-22-20 (removed IB 3-23-20 9-24-20 JR 3-19-20 3-19-20 moved IB 3-23-20 9-24-20 JN 3-20-20 3-20-20 moved MA 3-13-20 9-23-20 LF 3-20-20 10- 1-20 HS 3-20-20 3-20-20 9-21-20 SB 3-25-20 9-21-20 II 3-26-20 3-26-20 9-24-20 BF 4- 5-20 10- 1-20 UF 3-27-20 3-27-20 9-29-20 LF 4- 7-20 10- 1-20 SM 3-27-20 3-27-20 9-30-20 LG 4- 6-20 10- 1-20 AM 3-29-20 3-29-20 9-29-20 BG 4- 6-20 10- 1-20 CK 3-29-20 3-29-20 9-29-20 NF 4- 7-20 10- 1-20 FB 3-30-20 3-30-20 9-29-20 JF 3-26-20 10- 1-20 AA 3-30-20 3-30-20 9-23-20 LS 3-31-20 3-31-20 moved control removed MA 4- 5-20 9-30-20 FT 3-31-20 3-31-20 9-28-20 LP 4- 1-20 4- 1-20 moved HH 4- 6-20 10- 1-20

CHAPTER III.

DISCUSSION OF THE RESULTS

Statistical Study

The statistical study compared two groups of cases in respect to I.Q.

These groups were selected from one large group, on the basis of presence or absence of tonsillar defect. The tonsil group was composed of 236 cases, and the normal group, of 294. The distribution of the two groups according to intelligence is set forth in Table I, and in Figs. I and II.

TABLE I

Tonsil Group Normal Group

I.Q. No. of Per cent of No. of Per cent of Cases Cases Cases Cases

40- 50 2 8 0 0 50- 60 1 4 2 7 60- 70 7 29 4 14 70- 80 21 89 29 98 80- 90 45 190 52 177 90-100 80 339 107 364 100-110 55 233 67 228 110-120 17 72 24 81 120-130 6 25 9 30 130-140 2 8 0 0 140-150 1 4 0 0

Average 949 954 Median 953 956 Q 8705 827 [Sigma] 144 122

From these it is evident that the two groups are practically equal in intelligence. The average I.Q. for the normal group is 954, as compared with 949 for the tonsil group. The medians are equally close,--956 in the normal group and 953 with the tonsil cases. The difference in variability is negligible, Q being 8705 and [Sigma] 144 in the tonsil group, while in the normal Q is 827 and [Sigma] 122. The two cases with the lowest I.Q.'s were tonsil cases, but the three highest I.Q.'s also belong in this group.

Fig. 1. Distribution of I.Q.'s. Number of cases.

Fig. 2. Distribution of I.Q.'s by percentage of total number of cases in the group.

If the frequencies are expressed in terms of per cent of the total number of cases in the group, the two may be compared further. The following details are noticeable.

I.Q. Per cent of Per Cent of Tonsil Group Normal Group

Below 70 41 21 Below 90 320 296 Above 110 109 111 Above 120 37 30 Above 130 12 0

In other words, in the percentage of cases below normal intelligence, the tonsil group exceeds by 24 per cent. The percentage of defective cases is also slightly greater in the tonsil group--the difference here being 2 per cent. The normal group has a negligible predominance of bright cases,--only two-tenths of one per cent difference, while with the very superior cases, the tonsil group again exceeds,--by 12 per cent. The per cent of the tonsil group which reaches or exceeds the median of the normal is 49 per cent.

These figures seem to indicate remarkable similarity between the two groups considered. The two distributions are almost identical. While the slight predominance of cases below normal mentality in the tonsil group may indicate a very feeble tendency toward coincidence of tonsillar defect and mental dullness, it does not seem large enough to be at all significant. This is especially true when we consider that the tonsil group exceeds in superior children. If we allow the preceding contention of coincidence between dullness and tonsils, must we not argue here in the same manner for a tendency toward coincidence of superiority and tonsils?

The chief source of error in this part of the study is the fact that the throat examinations were not conducted by the same person throughout the investigation. For this reason there must have been some slight disagreement as to what should const.i.tute a reportable case. In the event, then, of a positive relationship between tonsil defect and lowering of the intelligence quotient, placement of normal tonsils in the "tonsil" group, and of diseased tonsils in the "normal" group would raise the first, and lower the second, thus tending to conceal the difference between the two. On the other hand, the cases where disagreement would occur would naturally be those of slighter defect, in which the intellectual r.e.t.a.r.dation would be less likely to occur, so that the result would probably be merely an increased height at the overlapping portion of the curves, with no change at the ends.

In any case, the two examiners had worked together previously, so that each must have been somewhat familiar with the opinions of the other.

They were aware, also, that p.r.o.nounced tonsillar defect was what we were attempting to detect. However this may be, there must always be some disagreement in diagnosis. When this is allowed for, the results of the investigation may be taken for what they are worth. Contrary to expectation, there seems to be very little difference in intelligence between a group of children whose throats are normal, and one in whom the tonsils are diseased or badly enlarged.

STUDY OF IMPROVEMENT AFTER OPERATION

The complete results of the tests and retests are collected in Table II, where each control case is listed immediately below its respective test case, and where age, height, weight, grip, tapping rate, I.Q., and score in Healy Picture Completion are shown. From these data the more detailed observations have been made. The improvement of each child in the various tests has been computed, and a comparison drawn between the two groups. As we have previously stated, any improvement shown by the test group in excess of that of the control group, may be looked upon as significant.

Let us consider first the improvement of the children in general health, as shown by height and weight. In Tables III and IV we have tabulated the results, in such shape as to permit of comparison. An inspection of these tables will establish the fact that after a six months' interval, the test group shows, in respect to height and weight, a very slight gain over the control group. In weight, the average of the amounts by which the test group gains exceed the control group gains is 137 lbs., and in height, only 16 inches. The medians of these amounts are 12 lbs. and 2 inches respectively. Comparing the improvements for the two groups, we find that in the case of the weights, the smallest gain (a loss of 12 lbs.) occurs in the control group, while the largest gain (107 lbs.) is in the test group.

TABLE II. RESULTS OF TESTS

Blank s.p.a.ces indicate where tests were omitted for one reason or another

N Age Weight Height Grip, Kg.

lbs. in. best hand

1 2 1 2 1 2 1 2

1 7- 7 8- 1 504 542 46 476 13 12 1C 8- 1 8- 7 535 572 464 478 11 13

2 6- 9 7- 3 409 429 426 411 9 9 2C 7- 1 7- 7 523 574 452 47 10 12

3 8- 8- 6 55 595 47 484 128 145 3C 9- 9 10- 3 615 629 517 529 14 15

4 8-10 9- 4 511 542 475 492 9 4C 9-10 10- 4 494 51 489 52 95

5 6- 1 6- 7 45 47 449 452 11 5C 8- 2 8- 8 562 57 466 481 12

6 5- 2 5- 8 438 445 431 439 8 6C 7- 1 7- 7 506 525 454 473 105

7 6- 7 7- 1 399 41 429 448 7 65 7C 6- 7 7- 1 384 387 419 432 9 10

8 8- 6 9- 608 633 508 518 10 8C 8- 5 8-11 454 521 468 476 15 16

9 9- 4 9-10 506 532 481 494 105 13 9C 9- 6 10- 598 614 519 552 165 21

10 6- 7 7-1 489 514 461 477 125 11 10C 7- 7-6 471 475 456 472 10 15

11 6- 7 7- 478 475 458 477 11 15 11C 6- 8 7-1 416 425 436 449 115 115

12 7- 8 8-2 48 525 448 14 12C 7- 1 7-8 41 445 415 433 6 45

13 13- 3 13-10 90 98 615 65 265 285 13C 14- 6 15- 747 768 568 578 22 23

14 11- 9 12-4 56 62 51 516 16 15 14C 11-10 12-4 819 86 579 583 22 24