Chapter 7. The Effect Of Environment On The IQ

The nature-nurture controversy has been raging among psychologists for years, and it is not surprising that both extremes, as well as those in the middle, have often tried to confirm their viewpoints by means of experiment (and all end up by placing the burden of proof on the opposition). Among these experiments are many which indicate that environmental influences can and do cause significant changes in the I Q; and while they do not "prove" the environmentalist point of view, their results are impressive enough to warrant much more consideration and evaluation than they have received from parents. If they are valid, as many people think they are, then they have far-reaching implications for parents and teachers.

These experiments have concentrated on several different types of problems: some have measured the impact of different environments on identical twins; some have studied the effect of institutional residence on the IQ, and others have investigated the influence of an improved home environment on the I Qs of foster children. Some have measured the effect of nursery-school attendance, and still others the influence of special training or coaching programs.

In a study of nineteen pairs of identical twins, most of whom had been separated from the first year and brought up in different environments, Horatio H. Newman, Frank N. Freeman, and Karl J. Holzinger found that "differences in educational and social environments produce undeniable differences in intelligence and scholastic achievements as measured by our tests."1 In other words, in individuals whose heredity is identical and who should, according to the hereditarian view, have the same native intelligence and the same I Q, there are marked differences, attributable only to environmental factors.

A study by Orlo L. Crissey2 and another by Harold M. Skeels and Eva A. Fillmore3 of the effect on the I Q of residence in such institutions as orphanages, juvenile homes, and schools for the feeble-minded indicate that there is a loss in IQ with prolonged residence in such places-a loss, incidentally, which is greater in the institutions for the feeble-minded than in the others.
There have been numerous studies of the I Qs of foster children, because they present researchers with many excellent opportunities for testing theories about heredity and environment. This is especially true of those children whose true parents had relatively low I Qs and whose foster parents had higher I Qs. If the hereditarian point of view is correct, these children should essentially resemble their true parents in respect to their I Qs, whereas if the environmentalists are right the children should resemble their foster parents more in this regard.

Marie Skodak4 made such a study of 154 children, of whom 140 were illegitimate. Most of the 154 came from hospitals or maternity homes, and all were less than six months old when adopted, the average age being 2.8 months. Data for a representative group of the 154 mothers show that 54 per cent had I Qs below 90, and 14 per cent had I Qs below 70. The social background and history of these women was characterized by impoverishment, institutional care, crime, mental defects, and similar factors.

Information obtained on 110 of the 154 fathers indicated that the average occupational status was in the lowest categories, 47 per cent of the 110 being day laborers, the lowest category.

The foster homes in which these children were placed represented a different social cross-section. Occupationally, 14 per cent were professionals, 23 per cent semi-professional and managerial, and only 1 per cent day laborers. The mean I Q for such a group would be above average.

The 154 children were twice given I Q tests, the first time when they reached the average age of two years and a second time when they reached an average age of four years and four months. The average I Q for the first test was 116; for the second it was 112. Of these 154 children, 139 were tested a third time when they reached the average age of seven years and one month. For this group of 139 the third average I Q was 113.

Now, since 90 to 110 is average, it is clear that these children had mean I Qs that were above average. From 55 to 65 per cent of them tested above average. Only 3 to 4 per cent tested below average. These results are very different from what the heredi-tarians would predict for such children. The environmentalist conclusion is that the great difference between the IQ levels of the natural parents and those of the children is the result of the beneficial influence of the environment of the foster home.

Irene E. Harms5 studied 107 children of mentally retarded mothers whose average I Q was 63. Information on 53 of the fathers indicated that 70 per cent were unskilled or semi-skilled laborers. The children were in an orphanage before they were six months old and were adopted before the average age of two years. At an average age of five years and five months, 87 of the 107 children were tested. Their average I Q was 106; only 8 of the 87 scored below normal, while 15 were superior; 40, or almost half, scored above average. This from children whose mothers were mentally retarded!

George S. Speer8 studied a group of underprivileged children placed in foster homes by a juvenile court after the death, desertion, or incompetence of parents. The homes they came from were of the lowest socio-economic level, extreme poverty, delinquency, disease, alcoholism, insanity, and mental disorders all being typical factors in their backgrounds. Of the 184 children studied, 68 had mothers who were mentally defective and were in state institutions; the median I Q of these 68 mothers was 49. Of the rest, 57 had mothers who were apparently normal; 59 of the children were studied without consideration of parental I Q.

Children Of Feeble-Minded And Normal Mothers

These figures show that the median I Q goes down as the numbers of year spent in an unfavorable environment increases. Of these 184 children, 59 were tested after being placed in selected foster homes. For those who were adopted before the age of three the median I Q was 103. For those who were adopted after the age of twelve the median I Q was 79. Speer concludes:

"If intelligence can be developed or improved by stimulating environmental situations . . . we believe that it should occur in this situation, after placement in this superior environment. And, as measured by the Binet I Q, it does. . . . The data indicate that the I Q of the child is directly affected by environmental conditions; it is depressed by inferior or limited environmental stimulation, and increases when the child is placed in a superior environment."

Perhaps even more impressive are the results of an experiment by Helen C. Dawe7 in which children living in an orphanage were given an intensive language-training program, designed to provide the children with verbal and informational experiences that they might normally have if they were living with interested parents. It was given to an experimental group which received about fifty hours of special training over a period of about three months, mainly on week ends. A matched control group received no training at all. The results showed that the experimental group gained on the average 14 I Q points while the control group lost 2 points. The resultant average I Q for the experimental group was 95, as against an average I Q of 80 for the control group. This result indicates that training in verbal skills alone raised the group's average from below normal to normal.

One of the best-known studies of the influence of environment on the I Q was conducted by Beth Well-man,8 who measured the effects of nursery-school experience on children from higher socio-economic levels than those involved in the studies mentioned before. Of the parents of the 652 children who were studied, 73 per cent of the fathers and 53 per cent of the mothers had from 16 to 20 years of education.

The average initial I Q for these children was 117. After one year of nursery-school attendance the average I Q gain was seven points. For 228 children who were tested after a second year of nursery-school attendance, the results showed an average gain of seven points for the first year and an additional four points after the second year. For the 67 children who were tested after a third year of nursery school, the average gain after the first year was eight points, after the second year four more points, and after the third year an additional two points. In all of these groups there were slight losses after each period of summer vacation, but the net gain for the second group was still ten points and for the third group eleven points. These are substantial gains for a group whose average I Q was high to begin with.

Finally, several studies9 have sought to determine the influence of special training or coaching programs on the I Q. These experiments have centered around coaching children with material identical to that found in a particular I Q test, or with material similar to that found in such a test. Some of these experiments have concentrated on coaching two groups, one with identical material and one with similar material, while other experiments have used one type or the other. The scores these children made upon being retested after the coaching period were then compared with the scores made by children in matched control groups who had received no special training.

There is no doubt whatsoever that such training significantly affects the I Q score. The influence of training with identical material is greater than the influence of training with similar material, but both are substantial. It is true that in both cases the changes do not appear to be permanent. The influence is greatest immediately after the training period and declines with the passage of time. Reduced but still significant gains have been measured as long as one year or more after the training period.

In Great Britain, where entrance to secondary schools that prepare students for a university education is based on results in an I Q test, parents and teachers have become increasingly concerned with raising I Qs through coaching. In fact, in recent years, special training or coaching for I Q tests has become so widespread that there has been public controversy over the question of whether or not all children should be coached. P. E. Vernon, one of Britain's leading psychologists, found an average increase of 11 points in I Q scores as a result of a few hours' coaching in material similar to that found in the I Q test. The average was 11 points; many of the increases were therefore greater than 11 points. And Vernon's results were supported, according to him, "by every other comparable research, carried out by six different investigators in three different countries, that has been done in this field."10

Hereditarians maintain that since this special training does not change an individual child's "intelligence" but only alters his I Q score for what seems to be a temporary period, the results confirm their theories. Environmentalists, on the other hand, see these results as indisputable evidence of the influence of environment. As for the increase apparently declining with the passage of time, they explain that as a child gets older he goes on to the more mature parts of the examination, for which he has not been coached.

As the I Q is used today, clearly the lack of a few points in a critical range can operate against a child's fullest development. And clearly the IQ can be raised. Whether in raising the I Q score we are raising the intelligence" or "capacity" or "ability" is an academic question that can be left for the psychologists to debate.