N[16]Test Group (A)Control Group (B)Test 1Test 3GainTest 1Test 3GainA-B124866·518·569·628·6-10·1240·947·9752·365·513·2-6·21456661081·99816·1-6·12871·378·57·274·285·811·6-4·4860·869·28·445·457·912·5-4·1165660·33·751·2553·8-·11147·8557·241·6475·41·8739·945·85·938·442·13·72·21048·956·77·847·151·84·73·1150·463·513·153·562·89·33·8451·160·29·149·454·24·84·32170·785·514·862·469·26·8813901122274·78813·38·719901081852·4596·611·435567·512·561·557·8-3·716·2Av.58·4569·5011·0155·1363·589·111·9M9·16·82·275%ile13·5212·675·2225%ile7·154·47-4·07Q3·184·14·65P. E. (distribution)3·814·196·1P. E. (average)±1·00±1·07±1·46Av. = 1·30 P. E.M. = 1·51 P. E.
6 months12 monthsAverage of gains in test group in excess of control1·371·90Median1·202·20P. E. of difference±·48±1·46Average in terms of P. E.2·851·30Median in terms of P. E.2·801·51
After a twelve months' interval, therefore, the actual average and median gains are slightly larger than after the first six months, but the variability is very much greater. Therefore, when expressed in terms of P. E., the gains are smaller. One of the test group cases (No. 13) who had gained 8 pounds after six months, gained 14 pounds in the second period of six months, making a total gain of 22 pounds. This gain is exceeded, however, by one in the control group (No. 12) who gained 3·5 pounds in six months, and 25·1 pounds more in the ensuing five months. This is certainly an enormous gain for five months, under any circumstances. Turning to Table XIV we find no corresponding gain in I.Q. for this child. Indeed there is a loss of five points.
Other children in the test group who made large gains, were case 12, with a gain of 18·5 pounds after twelve months, compared with 4·5 pounds after six months; case 19, gain of 6·3 pounds after first six months, and 18 pounds after 12 months; case 21, whose gain after the first period was 5·8 pounds, but who gained 14·8 pounds after twelve months. In these cases the gain in the second period greatly exceeds that for the first.
N[16]Test Group (A)Control Group (B)Test 1Test 3GainTest 1Test 3GainA-B1361·361·8·556·860·03·2-2·7242·645·93·345·249·84·6-1·32854·956·31·453·455·92·5-1·1850·852·31·546·848·71·9- ·41046·148·62·545·648·12·5·0146·049·73·746·449·73·3·41145·849·53·743·646·83·2·51651·653·51·948·750·11·4·51451·053·32·357·959·51·6·7347·050·23·251·754·02·3·9742·945·62·741·943·71·8·9447·550·53·048·950·81·91·11957·760·52·846·74·81·31·5Av.49·6352·172·548·7451·162·42·08M2·72·3·575%ile3·152·85·8525%ile1·61·75·92Q·775·65·885P. E. (distribution)·66·78·82P. E. (average)±·18±·22±·28Av.=·29 P. E.M.=1·79 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, 1·79 P. E. If these measures are compared with the results after the first period, we have:
6 months12 monthsAverage of gains of test group in excess of control·16·08Median of gains of test group in excess of control·20·50P. E. of difference·16·28Average in terms of P. E.1·00·29Median in terms of P. E.1·251·79
There seems to be little gain in height after the first period. Test cases 1 and 11 each show a gain of 3·7 inches after fifteen and twelve months respectively, compared with gains after six months of 1·6, and 1·9 inches. But case 2 in the control group, makes still greater comparative gain, +1·8 inches after six months and 4·6 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 1·4 inches in six months, and 3·3 inches after 15 months. This is practically equal growthwith test case 1. Control case 11 also shows relatively great growth during 12 months, +3·2 inches, whereas the growth in six months was only 1·3 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:
N[16]Test Group (A)Control Group (B)Test 1Test 3ChangeTest 1Test 2ChangeA-B8- 1+ 7+ 8-130+13- 516-16-17- 1-13- 9+ 4- 511- 3- 6- 3- 9-10- 1- 214-13- 6+ 7- 5+ 4+ 9- 219+ 6+10+ 4+ 1+ 7+ 6- 228- 7- 4+ 30+ 5+ 5- 210- 10+ 1- 6- 60+ 17- 8- 80- 7- 9- 2+ 22- 8- 4+ 4+ 9+10+ 1+ 34- 7- 4+ 3-15-150+ 310+ 6+ 6+ 8+ 5- 3+ 913-13+ 6+19-11-12- 1+203+ 6+13+ 7- 5-20-15+22Av.- 5-·544·46- 5·083·851·233·23M4- 2675%ile6·752·75325%ile- 2·502·75- 2Q4·6252·752·50P. E. (distribution)2·543·235·23P. E. (average)± ·71± ·90± 1·15Av.=2·81 P. E.M. =5·22 P. E.
6 months12 monthsAverage of gains of test group in excess of control1·833·23Median of gains of test group in excess of control4·006·00P. E. of difference·911·15Average in terms of P. E.2·022·81Median in terms of P. E.4·405·22
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:
N[16]Test Group (A)Control Group (B)Test 1Test 2GainTest 1Test 2GainA-B776-19145-6192220-215183-52910110155-42796-3891-41326·528·5222275-31012·512-·510122-2·5161918·5-·51010- ·5312·513·51414·5·514161712222·5·5·52116·515-1·51917-2·51131851115412311·5153·514·5161·5211111111·57·5-44Av.14·2714·61·3413·5415·191·65-1·31M01·5-1·575%ile1·253·75·6225%ile-1·38·12-·4Q1·311·81·51P. E. (distribution)1·341·652·31P. E. (average)± ·37±·46±·59Av.=-2·22 P. E.M.=-2·54 P. E.
6 months12 monthsAverage of gains of test group in excess of control-·24-1·31Median of gains of test group in excess of control-1·00-1·50P. E. of difference±·48±·59Average in terms of P. E.-·50-2·22Median in terms of P. E.-2·08-2·54
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. Itmay 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.
N[16]Test Group (A)Control Group (B)Test 1Test 3GainTest 1Test 3GainA-B21152154214917434-32131601761615018838-221135142710613428-2118133126- 71001088-1523150157712214119-121068145777014878- 1313614481351350820105122171501544131517219220140145515271081146115101-1420811312815131121-10252815017626178172- 632210513530152139-134311125120- 5155102-53481419022838175165-1048Av.133·47150·617·13134·6141·87·29·93M1541175%ile21·521·526·7525%ile5-10·75-16·5Q8·2516·1221·62P. E. (distribution)10·1317·222·07P. E. (average)± 2·67± 4·53± 5·26Av.=1·89 P. E.M. =2·09 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 months12 monthsAverage of gains of test group in excess of control- ·099·93Median of gains of test group in excess of control0·0011·00P. E. of difference±3·10± 5·26Average in terms of P. E.·031·89Median in terms of P. E.0·002·09
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 9·93, 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. Thecontrol 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.
6 months12 monthsAverage of gains of test group in excess of control-·020- ·060Median of gains of test group in excess of control-·015- ·090P. E. of difference±·040± ·036Average in terms of P. E.-·500-1·660Median in terms of P. E.-·380-2·500
N[16]Test Group (A)Control Group (B)Test 1Test 3GainTest 1Test 3GainA-B20-·10·03-·13·20·0·20-·3327·15·17-·02·09-·17·26-·2810-·09·27-·36·06·16-·10-·2614·09·05·04·13-·13·26-·2213-·03-·06·03·27·07·20-·1728·01·05-·04·17·10·07-·1115·03·03·0·18·08·10-·1023·11·0·11·06·0·06·0521·27-·01·28·29·14·15·1311·28-·04·32·11-·01·12·2018·14-·15·29·01·15-·14·43Av.·078·031·047·143·035·107-·06M·03·12-·0975%ile·153·20·0725%ile-·062·02-·275Q·107·09·172P. E. (distribution)·087·093·19P. E. (average)±·02±·03±·036Av.=-1·66 P. E.M.=-2·50 P. E.
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.