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Eye on Psi Chi: Fall 1997
The Cognitive Costs of Physical and Mental Health:
Applying the Psychology
of the Developed World
to the Problems
of the Developing World

Robert J. Sternberg and Elena L. Grigorenko, Yale University (CT)

Ill health, whether physical or mental, can have deleterious effects on cognitive functioning. Current research efforts are attempting to understand what these effects are and what can be done about them. In the course of this review, it is shown how the methods of psychology from the developed world can be applied to the problems of the developing world.

Suppose there were a malady that attacked very large numbers of American, British, French, or German children. The malady rarely resulted in catastrophic consequences, such as death or permanent disfigurement, although it did cause a variety of kinds of serious physical damage, such as stunting of growth, chronic diarrhea, and potential organ damage. More importantly for our purposes right now, it also had a cognitive effect: At moderate to high levels of infection, it resulted in stunting of cognitive--not just physical--growth, to the tune of, say, 5 to 7 IQ points.

The Problem
What, exactly, would the loss of 5 to 7 points of IQ mean? The first thing we need to realize is that we are not really just talking about 5 to 7 points of IQ. That's at an individual level. At a national level, in a moderate-sized country, say a mere 10 million children were affected. Then we are talking about 50 to 70 million IQ points. In a larger country with 100 million children affected, we are talking about perhaps 500 to 700 million points of IQ. The affected children may be losing not just IQ points, but other kinds of abilities as well, such as creative and practical intellectual abilities (Sternberg, 1985). What do such effects mean in practical terms, whether the losses are in the kinds of analytical abilities measured by conventional intelligence tests, or in creative or practical abilities?

At some level, we all know. Some supermarkets now have computerized cash registers that, seemingly, any moron can operate. There is no need, as there once was, actually to do any arithmetic computations, so the systems seem, on their surface, to be dummy-proof. A problem arises, however, not when the system is working perfectly, but when it isn't, as when the system is unable to handle a product that has not been bar-coded, or one that has been miscoded. That's what happened to one of us just a couple of weeks ago. The checker hadn't the faintest idea of what to do. Neither did the smiling so-called customer service representative. Meanwhile, the line got longer, and the author's patience wore thin. The supermarket lost him as a customer, and perhaps several other customers as well.

The other coauthor had an experience in a movie theater of wanting a cup of water. They had no water to offer. She asked just for a cup. They wouldn't give her a cup. She offered to buy just the cup for the price of a soda. They wouldn't sell the cup without the soda in it! She had to buy the cup with the soda, dump out the soda, and fill the cup with water from a fountain.

The malady we are talking about, though, does not affect just the children who later become supermarket checkers who quickly become check-mated, or soda jerks at movie theaters. It affects children who later become doctors, and maybe are not quite as accurate in diagnosing and treating illnesses as they might have been, or military leaders who do not really know how to negotiate with their opponents and who therefore see the battleground as the only solution, or defense lawyers who get confused and end up arguing effectively for the prosecutor rather than for their own clients. And it affects individuals in developing countries who must cope with often harsh and unforgiving environments.

The sad fact is that this malady is not just a single malady but a whole string of them: inadequate nutrition, ingestion of toxic substances, various kinds of parasitic infections, even severe anxiety or depression, and the like. These maladies are having right now the effects to which we refer above, but in countries where the kind of rapid, vocal, international press coverage that would be generated in the United States, United Kingdom, France, or Germany just doesn't come about; or when it does, no one seems much to care. What is worse is that all of these maladies are treatable, usually at low cost. But they often go untreated because of a lack of interest, or a lack of funds.

Are the effects debilitating? Absolutely. A team of us representing a collaboration among Yale, Moscow State, and Oxford Universities has recently reviewed the literature on different kinds of physical maladies, including micronutrient deficiencies of various kinds, ingestion of toxic substances, and parasitic infections of various kinds. One can argue about strengths of effects, which of course can vary with severity of insult (see, e.g., Ricciuti, 1994; Watkins & Pollitt, 1997). But we have arrived at what we believe is a straightforward conclusion: These maladies can make a significant unfavorable difference to cognitive functioning (Sternberg, Grigorenko, & Nokes, 1997).

At some level, we do not need even one research study to show the effects of these maladies. Almost everyone has experienced the effects themselves, although only acutely and at extremely low levels of intensity. All people have probably had at least one occasion on which they either missed dinner or had a very light dinner, and then didn't have time for breakfast the next morning. Maybe they even missed the lunch that should have preceded that dinner. Now it's about 11:00 a.m. the next day and they are perhaps sitting in a lecture hall listening to a complicated lecture on something that really doesn't interest them much; or perhaps they are giving the lecture. At that moment, they may be finding that the lecture interests them even less, because that lecture is the furthest thing from their mind--they are thinking about lunch. And they will get it.

Millions and millions of children, however, will not get that lunch, or will get a lunch so low in essential nutrients that they will still be hungry and nutrient-starved after the lunch. They probably won't get much of a dinner either, or breakfast. They are not thinking about what they are hearing either. For them, the teacher's droning voice is the furthest thing from their minds, as it will be tomorrow, and the next day, and the day after that.

The first time one of us took the tests we use for admission to college in the U.S.--the SAT--he was just getting over mononucleosis. He did not feel well at all. And he felt even worse when he took a final examination in college while he had a full-blown case of the flu. He could hardly concentrate on either test. He didn't totally fail either the SAT or the college examination. But his performance was compromised, as probably would be the performance of most people in similar situations, when they would have rather been, and would have been better off being, in bed.

Ironically, it is not just the disease that is debilitating them, but their own body (Nesse & Williams, 1994). Their body is telling them that this isn't the time for them to be engaging in strenuous mental activity, or, of course, physical activity. The body needs all the resources it can muster to fight the infection. It may even be generating a fever to create an environment that is hostile for the microorganisms that are attacking the individual, but an environment that also happens to be hostile to the individual's concentration on whatever he or she is doing.

Physical Well-Being and Analytical Abilities
A billion children are parasitically infected, and hundreds of millions, undernourished or malnourished (Bundy, 1994). Often the same children are both undernourished and infected. And their bodies are telling them that today--every day--isn't the day for serious mental effort. The result is that these children are likely to be building up a cumulative deficit in cognitive skills, which is likely to stay with them their whole life.

The Jamaica Study
Why do cumulative deficits remain? After all, many of these children later will become better nourished, or will rid themselves of the parasites infecting them. In order to answer this question, consider a collaborative study done in Jamaica by a team from Yale, the University of the West Indies, and the British Institute of Child Health, and funded by the Partnership for Child Development (Sternberg, Powell, McGrane, & Grantham-McGregor, 1997). The study was of the effect of whipworm infection (Trichuris trichiura) on cognitive functioning. Children typically acquire such infections when they put dirt in their mouths, and ingest worm eggs that are harbored in the dirt.

Sternberg et al. (1997) designed a battery of cognitive tests to be administered to Jamaican school children of elementary-school age (grades 4-5). The 196 children were asked to perform perceptual tasks, such as visually searching for a particular letter in an array of letters; a formboard task, which measured primarily perceptual-motor speed; memory tasks, such as remembering numbers or words; and reasoning tasks, such as solving analogies and series-completion problems. Some of the memory and reasoning tests were of the kinds found on typical psychometric tests of intelligence. The tests were administered twice, both to children who were infected with intestinal parasites (whipworm) and to ones who were not. Half the infected children were treated with an antiparasitic medication--albendazole--and the other half were administered a placebo (until after the study was over, at which time they were also treated with albendazole). All children took the tests before any kind of treatment, and then they all took the tests again later, after administration of either treatment or placebo, or, in the case of the uninfected group, after an equal amount of time had passed.

What did we find? We found, first, that the parasitically infected children, on the whole, performed at a lower level on the cognitive tests than did the noninfected ones, even after we controlled for obvious potential confounding variables, such as sex and socioeconomic status. Second, we found that the impairment in cognitive functioning was not equally distributed across the different kinds of tests. Rather, almost all of the impairment was in the memory and reasoning tests, which measure the kinds of functioning measured by tests of intelligence, and that are also relevant to success in school. Third, we found that treatment with albendazole resulted in no immediate increase at all in cognitive functioning. These results held up even when we controlled for effects of socioeconomic class differences.

Some of the more medically oriented types to whom we mentioned these results were surprised as well as disappointed that administration of the antiparasitic medication did not result in an immediate increase in cognitive scores. After all, if one takes a test while one has the flu, one's performance may very well be affected, but if one takes the test after one is over the flu, one's performance will quickly return to the higher level that it would have shown before one had the flu.

The difference in our study was that there was no prior higher level of performance to which to return. Many and probably most of the children had been chronically infected--maintaining infections and reinfecting themselves year after year. It is not hard for the children to do. All they have to do is get dirt in their mouths. With other kinds of parasites, such as schistosomes, which enter through the skin of the feet, the children only have to walk or swim in bodies of water in which the parasites reside in order to be infected.

Medication can potentially make a more nearly immediate cognitive difference. If one can get the children treated early, before infection becomes chronic, or if one tests children with only acute infections, the results of antiparasitic treatment can be immediate, dramatic, and lasting, as shown by Nokes and her colleagues (Nokes & Bundy, 1994; Nokes et al., 1992).

Parasitic infections can occur anywhere, even in the more developed countries (Bundy, 1994). Treatment is cheap and it is easy to administer. But we need more research on the cognitive and physical effects of the parasites, on treatments, and on the kinds of health-education measures we can provide that will be effective. Moreover, we need to develop effective cognitive interventions for children of all ages, because the effects not only of parasitic infections, but of poor nutrition cumulate, so that medical treatment is not sufficient to make up for the years that are likely to be lost when the children were not able to learn and think as effectively as they would have been able to had they not had these maladies. These interventions can be effective if only we have the will to implement them (see, e.g., Honig, 1994; Nickerson, 1994; Ramey, 1994; Sternberg & Grigorenko, 1997).

The Tanzania Study
Although there has been some research, the conclusions to be drawn are not unequivocal (Watkins & Pollitt, 1997). There are clearly effects, but different studies suggest different ones. In current research in Bagamoyo, Tanzania, which is sponsored by the Partnership for Child Development and which we are doing in collaboration with a team from Oxford led by Dr. Donald Bundy and coordinated by Dr. Kate Nokes, as well as a team from the University of Dar es Salaam led by Professor Akundaeli Mbise, we are investigating a kind of testing that may show an immediate effect of medical treatment, even for chronically infected children.

We believe that what a medical or nutritional intervention can do is to put children in a position where they are now able to learn. What it cannot do is put children in a position where they immediately recover the lost opportunities of the years during which they were infected. If our hypothesis is correct, then tests that actually allow learning at the time of testing may show immediate gains as a result of the medical or nutritional treatment. We are using such tests in our research. Thus, this research goes a step beyond the earlier Sternberg et al. (1997) study, in using dynamic rather than static testing. Such testing is called "dynamic testing," as opposed to the conventional static kind of testing to which we are accustomed in cognitive-ability assessments, which measure prior rather than current learning (Feuerstein, 1979; Grigorenko & Sternberg, 1997; Vygotsky, 1978). In this study with Tanzanian school children, we have been using three kinds of tasks.

The first is a syllogisms task, in which children are given problems such as "Alan is taller than Ken. Dan is taller than Alan. Who is the tallest, Alan, Ken, or Dan?" Children complete a pretest, then are given instruction in how drawings can be used to improve performance (e.g., one can imagine a line with Dan at the top, followed by Alan, and then, Ken), and then are given a posttest. The task is given in the children's language, Kiswahili, not in English.

The second task is a 20-questions task, where children are required to identify the object the examiner is thinking of. Again, there is a pretest and a posttest, with instruction in the middle on how maximally to narrow the field of possible objects. The third task is a sorting task, where children have to sort objects according to rules.

Our research is still in progress, but the preliminary results are promising. At the very least, we know that the tests are reliable, and that they measure skills somewhat different from those measured by conventional static tests. We do not know yet whether the tests will discriminate between the treated and untreated children. However, another study in which we do have results shows that dynamic testing can work, and that it can make a practical difference in skills needed for effective adaptation in developing countries by people from developed countries.

The Foreign Service Institute Study
In order to interact effectively with people abroad, one needs to know their language. The U.S. Foreign Service Institute trains government workers from many branches in the foreign languages they will need in order to work effectively abroad. In collaboration with Madeline Ehrman, we devised a dynamic test of foreign-language learning ability in which test-takers learned an artificial language--Ursulu--at the time they took the test (Grigorenko, Sternberg, & Ehrman, 1997). The test required the test-takers not only to learn the language, but also to show their knowledge as they learned it.

The artificial language itself was fairly complex, but not clearly related to any one particular language or language group. The test yielded oral and written scores, as well as scores on a number of language-learning skills. We were pleased to discover that scores on the test correlated more highly with scores on another test of foreign-language-learning ability than it did with conventional tests of intelligence, suggesting that the test is measuring, more or less, what it is supposed to measure. Moreover, and more importantly, scores on the test correlated about .7 with grades in foreign-language learning at the Foreign Service Institute--across the languages learned there. In other words, the dynamic test, in which one learned at the time of testing, was a very good predictor of who would be able to learn a new language well and then use the new language abroad.

Mental Well-Being and Practical Abilities
Virtually all of the cognitive testing that has been done has not only been static, but has also looked at what we believe to be a relatively narrow range of abilities. According to the triarchic theory of intelligence (Sternberg, 1985, 1988, 1996), intelligence involves not only analytical abilities, but also creative abilities and practical abilities.

The U. S. Studies
Our research on adults as well as children in the U.S. has revealed, for example, that practical intelligence is unrelated to the more analytical, or academic aspect of intelligence (Sternberg, Wagner, Williams, & Horvath, 1995). Put another way, some of the people who are highest in common sense do not test particularly well on intelligence tests.

For example, one study investigated bank vice presidents in a large bank chain, and found that measures of practical intelligence that required simulations of problems faced on the job predicted various kinds of performance ratings about twice as well as did IQ (Sternberg, Wagner, & Okagaki, 1993; Wagner, 1987). The measures the investigators devised did not correlate with intelligence-test scores, however.

It is important to realize that tests of practical intelligence, like any other tests, assume a set of values. What is valued in a given culture; what is not? Values enter in both with regard to the types of items used, and to how they are keyed. For example, the same items that might measure practical intelligence in one culture might measure nothing of consequence in another culture. Moreover, practical-intelligence items measuring appropriate behavior for a bank president or sales person might have to be scored differently across cultures. For example, the hard-driving sales techniques that might be valued in one place might not be valued at all in another. Consider a study we are doing in Kenya.

The Kenya Study
We are currently working with the Oxford team of Drs. Bundy and Nokes, Danish anthropologist Dr. Paul Wenzel Geisler of the Danish Bilharziasis Laboratory, and a Kenyan team led by Professor Frederick Okatcha of the Kenyatta University of Nairobi, to study the effects of parasitic infections on practical intelligence. What we want to know is whether these infections deprive children not only of IQ points, but of the common-sense, practical skills immediately needed to survive.

We are studying infected and non-infected children for their practical intellectual skills in treating their own infections, and are also investigating the relation of these skills to IQ-based skills, which we expect (consistent with the triarchic theory of intelligence) will be minimal. So far, we have piloted about 30 fourth- and seventh-grade students in Kissumu, Kenya.

We are giving two types of test. In the first test, children were presented with 101 words in their native language, Luo, 78 of which were names of real herbs and 33 of which were false-positive stimuli (nonherbs). The children were required to tick off the names of the real herbs, and for each real herb, to write the illnesses for which it could be used. The total recognition score was calculated so that respondents were penalized for false positive choices (saying a word represented an herb when it didn't). In the second test, children received an inventory with 29 different stories addressing illnesses and herbs used to treat those illnesses. Students had to show their knowledge of which herbs treated which illnesses. The correlation between the two tests was .50.

One of our preliminary findings, we believe, is quite interesting: The tests of knowledge of natural herbal medicines for treating infections correlated about - .45 with tests of conventional, crystallized intelligence, in particular, vocabulary tests whether administered in the English or the indigenous Luo language. In other words, children who are better socialized into the indigenous Kenyan rural culture are more poorly socialized into the formal school culture, and vice versa. Perhaps parents, and their children, make a choice in terms of their socialization.

The Kenya study underscores an important point about comparing cognitive functioning across cultures. One cannot merely go in and assume that whatever cognitive measures we use in our own culture measure the same thing in another culture. Some children in Kenya may have found the English-language vocabulary test intimidating. But imagine how children in the United States would feel if they were administered a test of natural herbal medicines used to fight various kinds of illnesses. For the most part, they would not be able to answer even a single test item correctly. Knowledge that is considered adaptive in the Luo rural culture here would be considered to be of little value; but the reverse can often be true as well. Adaptation is also differentially difficult in different places.

The U.S.-Spain Study
Practical intelligence is not fixed. It can be taught. In a study conducted in collaboration with investigators led by Dr. Howard Gardner at Harvard University, our team at Yale showed that practical intelligence can be effectively taught to urban, suburban, and rural school children at the grade 5 to grade 8 level, resulting in statistically significant and substantial gains in academic performance (Gardner, Krechevsky, Sternberg, & Okagaki, 1994; Sternberg, Okagaki, & Jackson, 1990). Experimental groups who received our Practical Intelligence for School Program (Williams et al., 1996) improved significantly more from pretests to posttests than did control groups who did not receive the program. Underlying this research is the notion that many children may actually have the academic abilities to do well in school, but not understand the expectations that the school has for them. This program has been translated into Spanish and used in Spain by Professor Jesus Beltran, of the Complutense University, with comparable results.

Nutrition and parasitic infections may have effects on practical intelligence that are different from the effects they have on the more academic aspects of intelligence. Indeed, children growing up in very challenging environments may have to develop skills that children in more privileged environments do not have to develop. What this means is that children could have a low level of IQ but a high level of practical intelligence, or a high level of IQ but a low level of practical intelligence. For sure, all of us know people of both kinds. Indeed, one of us was reading a newspaper a few weeks ago, and there was a story about the president of one of the larger banks in the U.S. The author was chagrined to realize that this very successful bank president was a student he had known who had been enrolled in his elementary and secondary schools, and had been a C student. In the U.S. this man was not labeled as "intelligent." Would he have been seen as intelligent elsewhere?

The Russia Study
Consider, for example, adaptation in modern-day Russia, which we are now studying with the support of the National Council for Eurasian and East European Research. The deceptively simple question "How are you?" can convey many different meanings. So, too, can the various possible answers to this query.
How do people answer the question "How are you?" when, unaccustomed to catastrophe, they are confronted by a war, earthquake, drought, or nuclear accident, or when their society as a whole undergoes tremendous change, causing significant financial and psychological strain?

To begin to answer this question, we conducted a study that explored various affective and cognitive dimensions of mental health and subjective well-being among mothers in Russia, where recent dramatic changes have affected the entire population. The current situation in the former Soviet Union provides an excellent opportunity for studying how people from all socioeconomic backgrounds are experiencing the stressful effects of financial, institutional, political, and societal uncertainty and instability. At this time of fluctuating values and beliefs, restructured economic and political institutions, and redefined standards of well-being and success, all citizens are feeling the stress of adapting to changing conditions. Such large-scale social upheaval has, in a sense, homogenized Russians from a variety of educational, national, religious, and other social groups. Consequently, we were able to investigate the differences and similarities in how people of different SES levels, marital statuses, ages, personality traits, and educational backgrounds experience large-scale societal change and to explore what determines people's perceptions of their adaptability and success in a radically changed society.

Four types of variables were investigated as indicators of women's well-being: (1) emotional well-being, as determined by the absence of anxiety or depression; (2) perceived control over one's life; (3) life satisfaction and attitude toward current societal changes; and (4) perceived change-related stress. This subjective well-being was explored in the context of four groups of variables previously identified as predictors: (1) demographic and job-related characteristics, (2) health-status indicators, (3) personality traits, and (4) level of family functioning.

In addition to these traditionally investigated predictors of contentment, we studied the contribution of intelligence to subjective well-being. Drastic societal changes have touched people at all levels of educational attainment and intellectual ability; the working class and the intelligentsia alike have found their incomes and lifestyles adversely affected by these transformations. In the majority of Western studies, people from different socioeconomic backgrounds have scored differently on conventional measures of intelligence, but sociological studies in Russia show that financial problems there are striking citizens regardless of educational level. Considerable anecdotal evidence suggests that many Russians are making dramatic career changes in response to societal transformation, but that others seem incapable of modifying or unwilling to modify their careers and to adjust to new realities. Consequently, dissatisfaction has increased, especially among those who have found themselves unable to provide for their families. This evidence has led us to explore the roles various types of intelligence play in channeling current societal changes through families. For this study, we relied on Sternberg's "triarchic theory of intelligence," which posits that intelligence can be structured in terms of a "triarchy" of abilities: analytical, creative, and practical. Specifically, we investigated the roles analytical intelligence and practical intelligence played in subjective well-being.

The sample included 494 women who were enrolled in the study through their children. Students from two different age groups (280 ten- and eleven-year-old children and 233 fifteen- and sixteen-year-old adolescents) attending public schools in Voronezh were asked to give their mothers a letter describing the study and requesting participation. Voronezh is a representative Russian city in which students from different socioeconomic backgrounds attend the same schools because few private specialized schools exist and residential patterns are such that prosperous and more financially strapped families live in close proximity. The mothers were invited to come to the school to fill out the relevant questionnaires. Mothers provided basic demographic data, such as age, income level, marital status, educational level, and number of children. Then, more extensive information on subjective well-being and predictive variables was gathered through a series of measures and questions.

An interesting finding concerns the role of intellectual factors in predicting various components of well-being. Specifically, practical abilities were associated with such aspects of subjective well-being as freedom from depression, life satisfaction, feelings of control over the present and future, and perception of current societal changes. In general, relatively high practical ability was associated with more adaptive feelings and behaviors. That is, mothers with strong practical abilities tended to be less depressed and to feel more in control of and satisfied with life than were those with lesser practical abilities. Yet, women who viewed recent societal changes as mostly negative tended to have high practical abilities. Certainly, life in Russian today is difficult: Salaries are not paid regularly, education and health care are undergoing major changes, political institutions seem fragile, and the danger of civil war still looms. It may be, then, that women with relatively high practical abilities simply perceive the present situation accurately and adapt, running their lives satisfactorily even in the context of shifting conditions that they view as negative.

Moreover, we found a significant link between high levels of crystallized abilities and two of the indicators of subjective well-being: (1) feeling of control over one's present life and (2) perceived stress associated with uncertainty about parenting and raising a family. Crystallized abilities were negatively associated with the perceived stress of raising a family, suggesting that women with high verbal intelligence tend to be less overwhelmed than do others by the challenges of the "new" life and to be more secure about transmitting "old" moral and educational values. Nevertheless, higher levels of crystallized abilities were associated with lower feelings of control over one's current life.

Another, somewhat surprising finding, was the low predictive power of recent so-called "life events." Only two of these events--the beginning of a career and retirement--were found to be related to subjective well-being.

This study has helped to illuminate the dynamics of well-being in a milieu of societal uncertainty and instability. These particular Russian experiences help us understand how human beings find satisfaction in their lives, even under tremendous amounts of external long-term stress. In addition, this exploration of the experiences of women--still the primary nurturers of future generations--contributes to a growing body of research on the role played by women's social and emotional well-being in children's maladaptive development.

The Taiwan Study
Cultures have different adaptive requirements related to intelligence, and even different conceptions of what intelligence is, or whether there even is such a thing as intelligence. The Chinese language, for example, has no single word that corresponds exactly to our word for intelligence. When we studied in Taiwan implicit theories (folk conceptions) underlying the word in Chinese that most closely approximates the English word for intelligence, we found five underlying factors (Yang & Sternberg, 1997). The first factor was similar to a general intelligence factor. The other factors were interpersonal intelligence, intrapersonal intelligence, intellectual self-assertion, and intellectual self-effacement. These factors were very different from those we had formerly obtained in the United States (Sternberg, Conway, Ketron, & Bernstein, 1981). In other words, one cannot just assume that, in other cultures, the conception of intelligence, or even what constitutes desirable cognitive abilities, will match our own. We need first to investigate the properties and conceptualizations of the culture in which we are working, preferably working with collaborators from that culture.

The bottom line is that in any study of cognitive abilities outside our own culture--including studies of the effects of physical ill health on such abilities and of the effects of these abilities on mental health--we must be very cautious in defining our constructs and in doing our research. We cannot merely assume that the cognitive skills we value, or label as intelligence, are those valued or labeled as intelligence in another culture. It is for this reason that we have collaborated with psychologists from the cultures in which we are working, and we have done analyses of conceptions of intelligence in these cultures rather than assuming that their notions of intelligence equal ours. Such understandings are needed to study the cognitive costs of ill health.

What We Know About Cognitive Costs of Ill Health
So what, exactly, are the cognitive costs of ill health? We believe several conclusions are supported by the best of the available data (Sternberg, Grigorenko, & Nokes, 1997):

With regard to poor nutrition, we know that short-term hunger results in impaired attention in school-age children, which leads to decreased academic performance. Long-term poor nutrition and protein-energy undernutrition, including kwashiorkor and marasmus, result in cognitive and social-emotional impairment, with little improvement upon nutritional recovery. Cognitive intervention for these children is a must.

With regard to specific micronutrient deficiencies, the evidence suggests that (a) low levels of dietary zinc can lead to a range of children's cognitive and social-emotional problems; that (b) iron deficiency, which is very common in some underdeveloped regions, leads to cognitive underachievement--including reduced IQ and reduced attention span--in both infants and schoolchildren, which can be reversed unless the children have developed severe cretinism; and that (c) vitamin A deficiency can lead to academic impairment, especially as mediated through effects on vision.

With regard to infections, (a) HIV infection, which has become increasingly common worldwide, typically has neurological effects that results in cognitive impairment; that (b) respiratory illnesses, unless severe, result in only temporary impairments that are reversible; and that (c) various kinds of worm infections, at high moderate to high levels, can result in cognitive deficits in high-level mental skills.

With respect to toxins, toxic substances, such as alcohol (usually absorbed in utero) and lead (usually absorbed through the environment, such as through eating of paint) can also result in moderate to severe cognitive impairments, in the case of alcohol, even at low doses.

The question now is what we are going to do about all this. Do we want to support the research and development? People can ask themselves what they would do if there were a malady--easily studied and treated, that was robbing their country of millions of IQ points; that was physically devastating the children in their country; and that it was in their power to treat. They can ask themselves whether, because of the loss in cognitive skills, it is worth not only the fiascoes in the supermarket and bank lines, but also in the wars that are fought for no need, because people have not developed the cognitive skills to think clearly and well.

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This article is based on the 1997 Psi Chi/Frederick Howell Lewis Distinguished Lecture, "Applying the Psychology of the Developed World to the Problems of the Developing World," presented by Dr. Robert Sternberg at the 68th Annual Psi Chi National Convention, held in conjunction with the 105th Annual Convention of the American Psychological Association, in Chicago, Illinois, August 15, 1997.
Preparation of this article was supported by the Partnership for Child Development, which is funded in part by the James S. McDonnell Foundation.
Correspondence concerning this article should be sent to Robert J. Sternberg, Department of Psychology, Yale University, Box 208205, New Haven, CT 06520-8205 USA. Electronic mail may be sent to

Copyright 1997 (Volume 2, Issue 1) by Psi Chi, the International Honor Society in Psychology



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