Catherine Nokes

The Relationship between Academic and Practical Intelligence: A Case Study in Kenya.

We worked in a rural village in Western Kenya to test the notion that academic and practical intelligence are separable and relatively distinct constructs. Eighty-five children (43 boys and 42 girls) between the ages of 12 and 15 years participated in the study. The main dependent variable of interest was their set of scores on a test of their tacit knowledge for natural herbal medicines used to fight illnesses. This kind of knowledge is viewed by the villagers as important in adaptation to their environment, which is understandable given that the overwhelming majority of the children have, at a given time, parasitic infections that can interfere with their daily functioning. We found that scores on the test of tacit knowledge correlated trivially or significantly negatively with measures of academic intelligence and achievement, even after controlling for socioeconomic status (SES). We suggest that, among these villagers, time spent developing academic skills may be perceived as taking away from time that needs to be spent developing practical skills and vice versa. The result is that academic and practical intelligence can develop independently or even at odds with one another.

Evidence for an association between hookworm infection and cognitive function in Indonesian school children

Summary The association between helminth infection and cognitive and motor function was investigated in school‐age children in Java, Indonesia. 432 children from 42 primary schools participated in the study. Children were stratified by age and sex into two age groups, 8–9 years and 11–13 years. Children infected with hookworm performed significantly worse than children without hookworm infection in 6 of the 14 cognitive or motor tests. After controlling for school (as a random effect) plus age, socio‐economic status and parental education, sex, stunting (height‐for‐age < − 2sd), body mass index, haemoglobin concentration and the presence of A. lumbricoides and T. trichiura infections, infection with hookworm explained significantly lower scores on tests of Fluency (P < 0.01), Digit‐Span Forwards (P < 0.01), Number Choice (P < 0.01), Picture Search (P < 0.03), Stroop Colour Word (P < 0.02) and Mazes (P < 0.001). In 4 of the 6‐tests (Fluency, Number Choice, Picture Search and Mazes), there was a significant interaction between hookworm infection and age (P < 0.03), indicating that the association between hookworm and lower test scores increased with age. No associations were observed between hookworm infection and scores in tests of Digit‐Span Backwards, Corsi‐Block, Stroop Colour, Stroop Interference, Free Recall, Verbal Analogies, Bead Threading or the Pegboard (P > 0.05). Tests associated with helminths represented various functions of working memory. No significant associations between helminth infection and motor function were observed that could not be explained by chance. The results suggest that hookworm infection can have a significant adverse effect on childrens working memory which may have consequences for a childs reasoning ability and reading comprehension. Although the results are only associational, the fact that differences in cognition were observed at baseline imply that preventing infection with helminths in school‐age children could be of benefit.

The organisation of Luo conceptions of intelligence: A study of implicit theories in a Kenyan village

This article examines the organisation of concepts of intelligence among the Luo people in rural Kenya. In particular, it discusses what the components of these concepts are; how these components are expressed in the DhoLuo language, how they are interrelated, how they are used in judgements of other people, and how these components of Luo conceptions of intelligence are related to Western conceptions of intelligence. Peer, teacher, and adult in the community ratings of children on Luo components of intelligence are correlated with performance on conventional ability tests and with school achievement. The Luo concept of intelligence is primarily expressed in the DhoLuo vocabulary by four concepts (rieko, luoro, paro, and winjo), which appear to form two latent structures, social-emotional competence and cognitive competence. Indicators of only one of these concepts (rieko) and only one latent structure (cognitive competence) correlate with scores on conventional Western cognitive ability tests and with school achievement in English and mathematics. The article also presents a novel method for analysing data from people’s ratings of each other’s intelligence that is useful when not every one who is providing the ratings knows everyone who is to be rated, and when Likert rating scales are inapplicable.

Assessing intellectual potential in rural Tanzanian school children.

What do conventional intellectual-ability tests tell us about the abilities of Black Africans living in non-Westernized environmental contexts? We examined an aspect of this question in a study employing dynamic testing, conducted in rural villages near Bagamoyo, Tanzania. A total of 358 experimental-group children in 10 schools, ranging in grade levels from 2 to 5, participated in the study. An additional 100 students of the same ages served as control participants. All experimental-group participants received three dynamic tests (administered in Kiswahili) of largely fluid intellectual abilities: Syllogisms, Sorting, and Twenty Questions. Each test given to the experimental group comprised administration of a separately scored (a) pretest, (b) intervention teaching cognitive skills and strategies contributing to success on that kind of test, and (c) posttest. Control participants received only the pretest and posttest. In addition, scores were available for the experimental-group children on reference tests of intellectual abilities and school achievement. We found that scores of children in the experimental group increased significantly from pretest to posttest relative to scores of children in the control group. Pretest scores of experimental-group children were relatively weak predictors of posttest scores, whereas pretest scores of control-group children were significantly stronger predictors of posttest scores. Posttest scores on the dynamic tests generally were better predictors than were pretest scores of the reference ability and achievement measures.

The impact of population level deworming on the haemoglobin levels of schoolchildren in Tanga,Tanzania

Summary The impact of albendazole (400 mg) and praziquantel (40 mg/kg body weight) treatment of schoolchildren was compared with placebo according to the presence of anaemia (haemoglobin concentration < 11.0 g/dl) and heavy (> 5000 epg) or light (< 5000 epg) hookworm egg load. The study was conducted in rural Tanga. Medication was administered in September 1994 and children were followed‐up in January 1995. Overall, anthelminthic treatment reduced the fall in haemoglobin concentration compared with that observed in the placebo group (− 0.11 g/dl vs. − 0.35 g/dl; P = 0.02). Anthelminthic treatment was of greatest benefit to the 9% of children with both anaemia and heavy hookworm egg load (+ 0.67 g/dl vs. − 0.67 g/dl) and was also of significant benefit to the 38% of children with anaemia and light hookworm egg load (+ 0.07 g/dl vs. − 0.21 g/dl). It was of no significant benefit to children who were not anaemic. This study suggests that single‐dose anthelminthic treatment distributed in schools in this area achieves haematological benefits in nearly half of children infected with S. haematobium and geohelminths (37% of total population).

Anthelmintic treatment improves the hemoglobin and serum ferritin concentrations of Tanzanian schoolchildren.

To investigate the relationships between helminth infections and iron status among school-aged children, 1,115 Tanzanian children in grades 2 through 5 were randomly assigned to treatment or control groups. The children in the treatment group were screened for infection with Schistosoma haematobium and hookworm at baseline, 3 months, and 15 months; infected children were given albendazole against hookworm and praziquantel against schistosomiasis. The control group received a placebo and did not undergo parasitological screening until 15 months after the baseline. Hematological variables were compared between the treatment and control groups. The main results were, first, that the hemoglobin concentration significantly improved after treatment for hookworm (p < .001) by 9.3 g/L in children treated for hookworm only and by 8.8 g/L in children treated for hookworm and schistosomiasis. The ferritin concentration also improved in children treated for schistosomiasis (p = .001) or hookworm (p = .019). Second, a longitudinal analysis of the data from the children in the control group showed that hookworm and schistosomiasis loads were negatively associated with hemoglobin and ferritin concentrations. Moreover, ferritin concentrations increased as C-reactive protein levels increased. Overall, the results showed that anthelmintic treatment is a useful tool for reducing anemia in areas with high hookworm and schistosomiasis endemicity. The empirical relationship between ferritin and C-reactive protein indicated that simple procedures for adjusting cutoff points for the use of ferritin as an indicator of low iron stores were unlikely to be useful in this population.

Alternatives to bodyweight for estimating the dose of praziquantel needed to treat schistosomiasis

Data on age, height and mid upper-arm circumference (MUAC) from nearly 6000 schoolchildren in Ghana, Tanzania and Malawi (not MUAC) were used to examine their power to predict bodyweight and thus the dosage of praziquantel required to treat schistosomiasis. Height was found to provide a simple and reasonably accurate estimate of weight, and about 75% of children would have been given a dosage of praziquantel within the range normally given using bodyweight at a dosage of 40 mg/kg bodyweight. The upper and lower ranges in dosage did not exceed dosages of praziquantel which have been used before or are currently recommended to treat schistosomiasis. A pole marked with the number of tablets could thus be used as a simple way to determine the dose of praziquantel to treat children in school-based health programmes.