13 613 618 5 568 60 32 -27 2 426 459 33 452 498 46 -13 28 549 563 14 534 559 25 -11 8 508 523 15 468 487 19 - 4 10 461 486 25 456 481 25 0 1 46 497 37 464 497 33 4 11 458 495 37 436 468 32 5 16 516 535 19 487 501 14 5 14 51 533 23 579 595 16 7 3 47 502 32 517 54 23 9 7 429 456 27 419 437 18 9 4 475 505 3 489 508 19 11 19 577 605 28 467 48 13 15

Av. 4963 5217 25 4874 5116 242 08 M 27 23 5 75%ile 315 285 85 25%ile 16 175 92 Q 775 65 885 P. E. (distribution) 66 78 82 P. E. (average) 18 22 28

Av.=29 P. E.

M.=179 P. E.

In weight, then, the mean gain of the test group over and above the control continues to increase through the second period of six months.

The variability, however, increases enormously, which fact is due possibly to varying conditions which may enter in during the longer period to affect the health and thus lessen the gain of some of the children.

In order to determine whether the slight inequalities in interval length have any considerable effect on the results, we have calculated the relation between the length of interval and amount of improvement. The coefficient of correlation by the method of rank differences is equal to 03. The small number of cases renders the unreliability of correlation very great, but we can at least say that there is no consistent relationship between improvement and time interval, within the narrow limits here set. We are probably justified in taking twelve months as the interval, since such was the case in eight out of the fifteen test cases, while the greatest variation above this made was four months, and below it, one month.

The gains in height after twelve months are shown in Table XVI. The average gain of test group in excess of control, is only 08 inches, and the median 5 inches. Variability is about the same as at the end of six months, P. E. 28. The average is only 29 P. E., but the median is a little larger, 179 P. E. If these measures are compared with the results after the first period, we have:

6 months 12 months

Average of gains of test group in excess of control 16 08 Median of gains of test group in excess of control 2 5 P. E. of difference 16 28 Average in terms of P. E. 100 29 Median in terms of P. E. 125 179

There seems to be little gain in height after the first period. Test cases 1 and 11 each show a gain of 37 inches after fifteen and twelve months respectively, compared with gains after six months of 16, and 19 inches. But case 2 in the control group, makes still greater comparative gain, +18 inches after six months and 46 inches after seventeen months. In this case there are almost six additional months for the child to grow, which may account for the larger gain. Control case 1, however, may be compared with his partner, mentioned above, since the interval between tests was the same for both. This boy grew 14 inches in six months, and 33 inches after 15 months. This is practically equal growth with test case 1. Control case 11 also shows relatively great growth during 12 months, +32 inches, whereas the growth in six months was only 13 inches. Out of the test group, 7 cases gained more in the first period of six months, than in the second, while only 6 gained more in the second than in the first. Of the control group, 7 cases made more than half of their total gain during the second six months of the total twelve months' period. Since this is true, it seems likely that whatever increase in growth we find during the second half of the twelve months' interval, may be explained by incidental causes, and that so far as actual gain in height is considered, there is no further effect from the operations, after six months.

As was mentioned in the previous chapter, height and weight are of less significance when considered alone, than when taken in relation to each other and to the age of the individual. The gain in this weight-height-age relationship following upon operation for adenoids and tonsils, will be considered in the same manner as were weight and height gains. We have, then:

TABLE XVII

Height-Weight Relationship, Second Retests, 13 Pairs Showing changes in per cent over or underweight after 12 months' interval

N[16] Test Group (A) Control Group (B)

Test 1 Test 3 Change Test 1 Test 2 Change A-B

8 - 1 + 7 + 8 -13 0 +13 - 5 16 -16 -17 - 1 -13 - 9 + 4 - 5 11 - 3 - 6 - 3 - 9 -10 - 1 - 2 14 -13 - 6 + 7 - 5 + 4 + 9 - 2 19 + 6 +10 + 4 + 1 + 7 + 6 - 2 28 - 7 - 4 + 3 0 + 5 + 5 - 2 10 - 1 0 + 1 - 6 - 6 0 + 1 7 - 8 - 8 0 - 7 - 9 - 2 + 2 2 - 8 - 4 + 4 + 9 +10 + 1 + 3 4 - 7 - 4 + 3 -15 -15 0 + 3 1 0 + 6 + 6 + 8 + 5 - 3 + 9 13 -13 + 6 +19 -11 -12 - 1 +20 3 + 6 +13 + 7 - 5 -20 -15 +22

Av. - 5 - 54 446 - 508 385 123 323 M 4 - 2 6 75%ile 675 275 3 25%ile - 250 275 -2 Q 4625 275 250 P. E. (distribution) 254 323 523 P. E. (average) 71 90 115 Av.=281 P. E.

M. =522 P. E.

6 months 12 months

Average of gains of test group in excess of control 183 323 Median of gains of test group in excess of control 400 6 P. E. of difference 91 115 Average in terms of P. E. 202 281 Median in terms of P. E. 440 522

The mean of the actual gains in the second period exceeds that of the first. Again the second group of results is more variable, decreasing the reliability. There seems, however, to be a definite increase in the net gain of the test group during a second six months' period. Some individual cases may be cited. The greatest gain after six months is 8 units in the test case, matched by an equal gain of 8 units in the control group. After twelve months, the test group shows one gain of 19 units, the highest gain in the control group being 13. Six cases in the test group, and 13 in the control had lost at the end of six months, but after twelve months, all but 2 of the test cases showed a gain, and all but 5 of the controls. In 10 test cases out of the total 13, more than half of the gain occurred during the second six months. In the control group, six of the cases made more than half of their gain during the second six months, and the second interval gains of the other 7 cases exceeded the 50 per cent mark by so little that they may be accounted for by chance.

These results seem to indicate a slight but actual increase in the net gain of the test group during the second six months of the experiment, and an accompanying growth in the variability of these gains.

It will be remembered that the results described in the previous chapter show no gain in strength of grip as a result of operation. Comparison of the 13 cases tested after the second interval, with the 16 cases at the end of the first, gives results as follows:

TABLE XVIII

Gain in Grip, Second Retest, 13 Pairs

N[16] Test Group (A) Control Group (B)

Test 1 Test 2 Gain Test 1 Test 2 Gain A-B

7 7 6 -1 9 14 5 -6 19 22 20 -2 15 18 3 -5 2 9 10 1 10 15 5 -4 27 9 6 -3 8 9 1 -4 13 265 285 2 22 27 5 -3 10 125 12 -5 10 12 2 -25 16 19 185 -5 10 10 0 - 5 3 125 13 5 14 145 5 0 14 16 17 1 22 225 5 5 21 165 15 -15 19 17 -2 5 1 13 18 5 11 15 4 1 23 115 15 35 145 16 15 2 11 11 11 0 115 75 -4 4

Av. 1427 1461 34 1354 1519 165 -131 M 0 15 -15 75%ile 125 375 62 25%ile -138 12 -4 Q 131 181 51 P. E. (distribution) 134 165 231 P. E. (average) 37 46 59 Av.=-222 P. E.

M.=-254 P. E.

6 12 months months Average of gains of test group in excess of control -24 -131 Median of gains of test group in excess of control -100 -150 P. E. of difference 48 59 Average in terms of P. E. -50 -222 Median in terms of P. E. -208 -254

The greatest gain in the test group after twelve months is 5 Kg. (Case 1). During the first six months this case lost 1 Kg. There are two gains of 5 Kg. in the control group. Of these two (cases 7 and 13) had gained 1 Kg. during the first interval and another (case 2) 2 Kg. The greatest loss in the test group after the twelve months' period was 3 Kg., by case 27, which had already lost this amount at the end of six months.

The greatest loss in the control group was suffered by case 11, a loss of 4 Kg., all in the second period. After the first period, 9 out of 16 cases in the test group gained in strength of grip, and 13 in the control group. After the second period, the test cases showing gain numbered only 7 out of 13, while all of the control cases had gained except 2. Of the test group 8 cases in the second period either gained less than half of the amount they had improved in the first period, or dropped from the scores they had made at that time. The corresponding numbers for the control group are 6 and 7.

There is evidently no improvement in strength of grip twelve months after operation. The unreliability of the results is very great.

However, there is certainly no tendency toward improvement. Why this should be is a question. It may be that the change in examiners is partly responsible, for performance in this test is influenced to a surprising extent by the manner in which it is presented.

TABLE XIX

Tapping--Second Retest, 15 Pairs

N[16] Test Group (A) Control Group (B)

Test 1 Test 3 Gain Test 1 Test 3 Gain A-B

21 152 154 2 149 174 34 -32 13 160 176 16 150 188 38 -22 1 135 142 7 106 134 28 -21 18 133 126 - 7 100 108 8 -15 23 150 157 7 122 141 19 -12 10 68 145 77 70 148 78 - 1 3 136 144 8 135 135 0 8 20 105 122 17 150 154 4 13 15 172 192 20 140 145 5 15 27 108 114 6 115 101 -14 20 8 113 128 15 131 121 -10 25 28 150 176 26 178 172 - 6 32 2 105 135 30 152 139 -13 43 11 125 120 - 5 155 102 -53 48 14 190 228 38 175 165 -10 48

Av. 13347 1506 1713 1346 1418 72 993 M 15 4 11 75%ile 215 215 2675 25%ile 5 -1075 -165 Q 825 1612 2162 P. E. (distribution) 1013 172 2207 P. E. (average) 267 453 526 Av.=189 P. E.

M. =209 P. E.

There were 15 pairs of cases who performed the tapping test at the end of twelve months. Comparison with the 21 pairs after six months yields the following results:

6 months 12 months

Average of gains of test group in excess of control - 09 993 Median of gains of test group in excess of control 0 11 P. E. of difference 310 526 Average in terms of P. E. 03 189 Median in terms of P. E. 0 209

The gain in the second interval is greater for the tapping test than for any of the tests yet described. After the first six months there is no gain. At the end of ten months the average gain is 993, and the median 11 taps per half minute. After six months' interval, 11 of 21 test group cases had lost. At the end of twelve months, only 2 out of 15 had lost.

The control group, on the other hand, lost in 11 out of 21 cases after six months, and in 6 out of 15 at the end of twelve months. All but one of the test group cases made more than half of their gain in the second period. Of the control group only 7 cases did this. The variability of gains after 12 months is about equal to the variability at the end of six months.

Strangely enough, decrease in fatigueability as described in the previous chapter does not show itself after 12 months. In fact, the negligible loss in ability noticeable after six months has increased after a period of twelve months. In only 4 out of 11 test group cases, is the gain in the second period equal to that of the first, a similar result to that found in the control group, where 5 out of the 11 cases made half their total gain in the second interval. The results are compared below.

The point of greatest interest in the present study is, as has been said, improvement in intelligence. Does operation for adenoids and tonsils result in improvement in intelligence, as measured by I.Q.? If such improvement does not manifest itself after six months, can it be found after a second period of the same length? The latter question is answered by observation of Table XXI and attention to the following facts, gathered from the 21 pairs of cases who were given intelligence tests after the twelve months' interval.

6 12 months months Average of gains of test group in excess of control -1035 -314 Median of gains of test group in excess of control -1 -3 P. E. of difference 110 184 Average in terms of P. E. - 94 -171 Median in terms of P. E. - 99 -163

The result after twelve months remains the same as that after the six months' interval. A gain or loss of two or three points in I.Q. is negligible, so that the mean gain of the test group in excess of the control is practically zero at the end of each period. Variability increases with the length of the interval. One case in the test group (case 4) gained nothing in six months, but showed a gain of 15 points after 13 months. However, there is a control case to match this,--case 15, who gained 1 point in the first six months and 20 points after 10 months. Case 20 in the test group lost 4 points in the first six months, but gained back these and 10 additional in the second period. But control No. 1 gained 5 points in the second interval after having lost 4 in the first.

On the other hand several cases lost in the second period, as compared with the first. Test group case 7, for example, gained 8 points in the first six months, and lost 6 of them in the second. Case 3 in the same group lost 3 points in the first period, and failed to regain any of them. Case 12 lost 3 points in six months and 9 more before the end of 12 months. In the control group, case 23 gained 15 pounds in the first six months and lost eight of them in the second. Summing up gains and losses in the second period, for both groups: