Intellectual Ability In Children Research Articles

2 Sex difference of Developmental Neurotoxicants on Intellectual Abilities: A Systematic Review and Meta-Analysis

Objective:Early life exposures to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been associated with diminished IQ scores in children. Some studies suggest that these neurotoxicants impact boys and girls differently. We conducted a systematic review and meta-analysis to identify and quantify sex differences in IQ deficits from pre- and post-natal exposures to these developmental neurotoxicants.Participants and Methods:We used PubMed and PsychINFO to screen abstracts of articles published between January 1, 1950 and December 31, 2021 for empirical studies of six neurotoxicants [lead, mercury, PCBs, PBDEs, OPPs, and/or phthalates] that (1) used an individualized biomarker; (2) measured exposure during the prenatal period or within the first six years of life; and (3) provided different effect estimates on children's intellectual abilities by sex. We assessed each study for risk of bias using Navigation Guide (Woodruff & Sutton, 2014). For studies with combinable data, we performed separate random effects meta-analyses for boys and girls with subgroup analyses by neurotoxicant. To homogenize the magnitude of effect observed in each study, we recalculated results to be expressed as the absolute change in intellectual abilities for a relative change of 1.5 times (i.e., 50% increase) in the exposure variable.Results:Of 3205 studies screened, 53 met inclusion criteria: 34 evaluated prenatal exposure, 11 postnatal exposure, and 8 both pre- and post-natal exposure. We generally rated these studies as "low" to "probably low" risk of bias. Among the studies examining prenatal exposure, 27 reported no significant differences between the sexes, 7 found negative associations in boys, 4 found negative associations in girls, 5 found negative nonsignificant associations in boys and positive nonsignificant associations in girls, and 3 found no clear pattern, where differences by sex depended on the specific phthalate compound or outcome measurement. Among the studies examining postnatal exposure, 14 reported no significant differences between the sexes, 1 found a negative association in boys, 2 found negative associations in girls, and 2 found positive associations for either boys or girls. In our meta-analysis of 16 studies (4 lead, 4 mercury, 2 PBDEs, 2 OPPs, 4 phthalates), we found that prenatal exposure to developmental neurotoxicants was associated with decreased full-scale intelligence in boys (B = -0.26; 95% CI: -0.45, -0.08), but not girls (B = 0.09; 95% CI: -0.14, 0.31). In subgroup analyses by neurotoxicant, prenatal exposure to lead (B = -1.07; 95% CI: -1.63, -0.52), and ZPBDEs (B = -0.57; 95% CI: -1.14, -0.01) were associated with decreased full-scale intelligence in boys, whereas the girls' effect sizes were consistently near zero.Conclusions:During fetal development, boys appear to be more vulnerable than girls to IQ deficits from neurotoxic exposures, and especially from lead and PBDEs. More research is needed to examine the nuanced sex-specific effects found for postnatal exposures to toxic chemicals.

Historical and Pedagogical Aspect of the Development of the Academic Talent of Students in Abroad Theory and Practice

This article is devoted to the one of the aspects of the students’ academic giftedness development in foreign theory and practice, which related to the history of pedagogy. The purpose of the article is to analyze the historical and pedagogical aspect of the development of academic giftedness of students in foreign theory and practice. The following used research methods were decisive as analysis and generalization of scientific and methodical sources, synthesis of the obtained data. Results. Academically gifted children have been found to have many needs that cannot be met by the standard education system. Therefore, in most educational institutions in Europe and the USA, programs for working with academically gifted children were designed and, in connection with this, the professional training programs for teachers were seriously changed and supplemented. An important role in the development of professional training of teachers who work with gifted and talented children is played by international organizations that research giftedness. Accumulated domestic and foreign experience on this problem shows the relevance of further development of theoretical foundations and practical ways of developing the academically gifted children education system. Conclusions. The peculiarities of the development of the education system for academically gifted children in the USA have been identifies by the author of the article as following: the deepening of profile and level differentiation of education; wide use of internal differentiation methods; the variability of forms of individualization of education; increase in the number of special educational institutions, departments and streams; the use of pedagogical mentoring programs. The specific peculiarities of the education content and methods of teaching gifted children, which consist in the application of accelerated learning and courses of «expansion» and «enrichment» of the program; increasing the role of effective teaching methods, modern technical means in the development of children's intellectual abilities. The author of the article concludes that for the successful intellectual development of children, as long-term practice shows, it is not enough to have a well-organized, systematic, intense general educational work in an educational institution, a necessary condition for this is the use of scientific concepts and methods for the problem of identifying and developing giftedness.

The influence of a child's intellectual abilities on psychological trauma: The mediation role of resilience

ObjectivePsychological trauma exists in children and has a real impact on their mental and physical health. There is mixed evidence that post-traumatic stress disorder can be influenced by a child's intellectual abilities. This study analysed whether resilience mediates the link between intellectual abilities and post-traumatic stress disorder in children. MethodsParticipants were children (N = 30) from 6 to 12 years of age. They completed a detailed history, took an intellectual quotient test, and answered questionnaires about their resilience and their post-traumatic stress symptoms. ResultsResults showed that the higher the children's visual spatial skills, the more resilient they were. Then, our analyses indicated that the higher the children's verbal comprehension skills, the fewer the symptoms of psychotrauma they presented. Moreover, our results showed that cultural resilience mediates the relationship between children's verbal comprehension skills and their symptoms of psychotrauma. ConclusionCultural resilience and verbal comprehension skills emerged as important protective factors. This study suggests that early prevention intervention may target children with lower cognitive abilities, and that social and cultural support should be considered ways of prevention for psychotrauma.

PELUANG DAN TANTANGAN PENDIDIKAN ANAK PADA ERA PANDEMI BAGI WANITA KARIR DI IAIN BONE

This research discusses the opportunities and challenges of children’s education in the pandemic era for career women at IAIN Bone. This study aims to understand the opportunity for children’s education in th pandemic era for career women in IAIN Bone and the challenges of children’s eduacation in the pandemic era for career women in IAIN Bone. This research is a field research with qualitative research, using pedagogical and psychological approaches using observation data collection methods, interviews, and documentation. Data collection techniques and data analysis use data clots as well as data reduction, data presentation, and conclusion drawings.The results showed that the first child education for women was because it made a necessity and more oppurtunities to be familiar with children to spend time together with shared sports, eating together, learning together, even gardening together. Parents better understand the child’s character and intellectual abilities of children, children can master learning with technology. Second, one the other hand, child psychological burden increases because it is often burdened with various tasks of the subjects that accumulate, for example when in one day there are three subjects, there are three tasks given by educators with the same deadline so sometimes making saturated children in learning.

Let’s Stop Complaining That Early Childhood Assessments Do Not Predict IQ

This Viewpoint discusses the concern about the long-term predictive validity of early childhood development (ECD) assessments and how this concern reflects a misunderstanding of the constructs of ECD and intelligence, how they are assessed, and the myriad of other influences on the growth and trajectory of intellectual ability in children.

Anatomical and clinical aspects and outcomes of bilateral cochlear implantation in cochlear hypoplasia type IV - a case report

Cochlear hypoplasia is a congenital inner ear malformation (IEM) characterized by a reduced external cochlear dimension, usually accompanied by an abnormal internal architecture. Type IV cochlear hypoplasia is a cochlea with hypoplastic middle and apical turns. It may occur along with dislocation of the facial nerve, associated with semicircular abnormalities, less clearly marked promontory, or stapedial fixation. Such patients can present a broad spectrum of audiological test results, from sensorineural or mixed mild or profound hearing loss. The above anatomical changes may be responsible for intraoperative difficulties during cochlear implantation. In the studied case, a 6-month-old patient was diagnosed with an inner ear malformation - cochlear hypoplasia type IV on both sides. Computed tomography with multiplanar and 3D reconstruction was performed to analyze the middle and inner ear anatomy in detail. Both types of imaging reconstruction helped decide which cochlear implant electrode to choose. Perimodiolar-positioned cochlear implant electrode was found to be the most suitable choice. The patient underwent sequential bilateral cochlear implantation with expected incomplete electrode array insertion on both sides. First repeatable auditory responses were observed two months after the second implant activation. Good parental cooperation with therapists and adequately defined developmental goals in the presented patient allowed the multidisciplinary team to take advantage of the child's intellectual abilities and choose the suitable communication method; however, the patient's auditory responses were obtained slowly. The final auditory results cannot be predicted in inner ear malformations due to abnormal anatomical structure and, thus, heterogeneous innervation within the deformed cochlea. The programming of the sound processor must be individual in each case, based on the child's behavior observation and, if possible, objective test results. Patients with cochlear malformations usually require higher stimulation intensities to obtain sound sensations than patients with a typical cochlear structure.

Normative Spiritualization of Parents in The Dynamics of Children's Intellectual Intelligence

The enthusiasm to hone children's intellectual intelligence abilities today is minimal as time goes by; this is due to environmental facilities, and there is no interest in knowledge, and most parents do not know that the knowledge gained by children also depends on the seriousness of parents physically and spiritually, with This researcher intends that parents are not only more concerned with physical sincerity, but also spiritual sincerity, just like 15th-century parents who gave birth to significant figures, even though the environmental facilities are elementary, but the product of thought or invention is influential to this day. This study uses a descriptive qualitative approach with library and field research methods. In contrast, data analysis uses the Milles and Huberman model, with a flow of information reduction, information arrangement, and concluding. The result of this study shows that the normative spiritualization of parents can influence simple intellectuals and progressive intellectuals. There is also a relationship between simple and advanced means, which impact originality and unoriginality.

Relationship between psychological adjustment and quality of life among parents with autistic child

Background: Autistic Disorder is a complicated childhood developmental disability that can have a severe impact on a child's intellectual, social, and language abilities, The number of children diagnosed with Autistic Disorder has risen dramatically, leaving a large number of children and their parents in need of comprehensive support services, Parenting a child with Autistic Disorder has been reported to disrupt the entire family's life and cause a slew of economic, social, physical, and psychological issues. Objective: The study aims to find out the relationship between Psychological adjustment and parents' quality of life. Method: The descriptive correlational study design approach is carried out by questioning individuals of the research population with the goal of describing the phenomena simply in terms of its type and degree of existence. Interrogating study participants about their psychological adjustment and quality of life is how the correlational approach is used. Results: there is a highly significant relationship (Strong positive) between psychological adjustment and quality of life at p-value= 0.001 which reflects the quality of life improves with increasing psychological adjustment.

Можливості корекції психоемоційного стану дітей із міопією засобами плавання

Children's low vision is one of the world's pressing health problems. The problem of myopia is due to its prevalence among different groups of the population, the high incidence of young people. Myopia is one of the main causes of myopia and disability in patients of this nosological group, which occupies a leading place among human visual pathologies. The article considers the possibilities of correcting the psycho-emotional state of children with myopia by swimming, the study of the impact of these tools on the psycho-emotional state of students with myopia (development of methods for correcting psycho-emotional state, which promotes proper use of exercise in classes with children with myopia). The main theoretical problem of corrective swimming of children with myopia was to substantiate the specifics of the content, means and methods of corrective action, which, in contrast to general didactic principles of teaching, based on understanding the structure of the primary defect and the peculiarity of development of visual impairment in order to increase the psycho-emotional state of visually impaired children of primary school age. The need for corrective work in the process of swimming was confirmed throughout the study. The process of teaching swimming to children with myopia, which depended on a number of conditions (creating comfort for visual functions, correct construction of training taking into account the characteristics of children with myopia, individual-differentiated approach, providing a positive emotional attitude to classes, taking into account the child's health) development of physical, psychomotor and intellectual abilities of children and adjusted a number of psychohygienic and psychophysical processes, as well as provided a high level of physical and mental health of children with myopia.

Underweight among Children under TwoYears in Indonesia

Underweight, have an impact on low cognitive, productivity, and intellectual abilities in children. Thisstudy aimed to analyze ecologically the factors related to underweight among children under two years inIndonesia.The study conducted using secondary data from the Indonesia Ministry of Health official report.Apart from the prevalence of underweight in children under two years, four other variables analyzed asindependent variables were the percentage of population passing Junior High School, poor population,exclusive breastfeeding, and prevalence of low birth weight.Data were analyzed using cross-tabulation.The results showed there was no relationship between the prevalence of underweight in children under twoyears with the percentage of population passing Junior High School and the percentage of poor population.Meanwhile, there is a positive relationship between the prevalence of low birth weight with the prevalenceof underweight in children under two years. The higher the prevalence of low birth weight, the higher theprevalence of underweight in children under two years. Moreover, the study found the higher the percentageof exclusive breastfeeding, the lower the prevalence of underweight in children under two years in a region.The study concluded that ecologically two variables have an ecological relationship with the prevalence ofunderweight in children under two years, namely the prevalence of low birth weight and the percentage ofexclusive breastfeeding.

Study of exposure to dexamethasone among children with acute lymphoblastic leukemia and effect on intellectual function – A pilot study

Background: There has been significant increase in the remission rates for childhood acute lymphoblastic leukemia (ALL) with addition of corticosteroids to chemotherapy regimens. However, with increase in survivors, there has been increase in the incidence of neurocognitive dysfunction as a 'long term sequelae. The present study was undertaken with the aim to study the effect of a chemotherapy regimen with dexamethasone on intellectual abilities in children with ALL. Methodology: This was a prospective, observational, and descriptive study conducted at a tertiary care hospital over a period of 18 months. Sixty children aged between 6 and 12 years diagnosed with B cell ALL and belonging to the standard risk ALL group on treatment protocol Pediatric Berlin-Frankfurt-Munster (1–10 years) (standard risk), initiated and maintained on oral dexamethasone as part of their chemotherapy regimen were recruited. All the patients were followed up for 6 months and assessed for intellectual ability using Raven's standard progressive matrices (SPM), which was carried out before starting oral dexamethasone, at 3 months and after 6 months of starting oral dexamethasone. Results: The scores obtained at three intervals were compared by one-way repeated analysis of variance and the results showed a significant increase in raw scores of SPM. The difference between the mean scores at the three specified intervals was statistically significant (P < 0.001). The overall maximum improvement (mean raw scores of 5.5) was seen over 6 months period in older age group (12 years). Gender-wise comparison of performance revealed an overall better scores in males, though the differences were not significant. Conclusion: The current study revealed a significant increase in raw scores of SPM in children with standard risk B cell ALL undergoing chemotherapy along with dexamethasone. However, randomized control studies with larger sample size followed up longitudinally for a longer period of time are needed for specific recommendations of using dexamethasone over other corticosteroids.

Theoretical and methodological aspects of the development of children's intellectual and creative abilities on the basis of media education technologies

The article deals with the theoretical and methodological aspects of the development of intellectual and creative abilities of children based on media education technologies. The main approaches that have developed in the world of science to this issue are studied, and the differences between them are outlined.Media literacy is, in general, a set of skills and abilities that enable people to analyze, evaluate, and generate information in different forms, genres, and types of different media. It is based on a model that encourages a person to ask questions about what they see, read, and hear. Through media literacy, a person acquires the ability to analyze media texts and distinguish the true from the false, the important from the insignificant, the narrow approach from the broad approach.

Age of walking and intellectual ability in autism spectrum disorder and other neurodevelopmental disorders: a population-based study.

Delayed walking is common in intellectual disability (ID) but may be less common when ID occurs with autism spectrum disorder (ASD). Previous studies examining this were limited by reliance on clinical samples and exclusion of children with severe motor deficits. To examine in a population-based sample if age of walking is differentially related to intellectual ability in children with ASD versus other neurodevelopmental disorders (NDD). Participants were from the nested Autism Birth Cohort Study of the Norwegian Mother, Father and Child Cohort Study (MoBa). Cox proportional hazards regression assessed if diagnosis (ASD n=212 vs. NDD n=354), continuous nonverbal IQ, and their interaction, were associated with continuous age of walking. The relationship between nonverbal IQ and age of walking was stronger for NDD than for ASD (Group×nonverbal IQ interaction, χ2 =13.93, p=.0002). This interaction was characterized by a 21% decrease in the likelihood of walking onset at any given time during the observation period per 10-point decrease in nonverbal IQ (hazard ratio=0.79, 95% CI: 0.78-0.85) in the NDD group compared to 8% (hazard ratio=0.92, 95% CI: 0.86-0.98) in the ASD group. The finding that age of walking is less strongly related to low intellectual ability in children with ASD than in children without other NDDs supports the hypothesis that ID in ASD may result from heterogeneous developmental pathways. Late walking may be a useful stratification variable in etiological research focused on ASD and other NDDs.

Intellectual Abilities of Children with Narcolepsy.

High cognitive functioning could be a protective factor for school difficulties, behavioral and mood impairments in children with narcolepsy. To investigate this factor, we studied the intellectual abilities of 74 children with narcolepsy (43 boys, 11.7 years old at diagnosis, 91% of cataplexies, 64% obese, 100% HLA positive for DR-DQB1*06:02). All children underwent a one-night polysomnography followed by Multiple Sleep Latency Tests, an evaluation of intelligence quotient (IQ), and filled standardized questionnaires. Thirty-eight percent had high potentialities (HP defined by IQ > 130) and 48% had school difficulties. Using non-parametric tests, we found that HP children reported less difficulties at school and tended to have less impulsivity, conduct, and learning disorders than those without HP. They also tended to be less obese and had less desaturation. Using a multivariate regression analysis, we found an association between the REM sleep percentage and the IQ. REM sleep could be involved in the dynamic changes contributing to the equilibrium of intellectual functioning. This study highlights that despite their frequent school difficulties, narcolepsy per se is unlikely to be a cause of intellectual disability in children. Prompt diagnosis and management of comorbidities such as obesity and obstructive sleep apnea (OSA) could improve cognitive and school performances in these children.

Evidence for the placenta-brain axis: multi-omic kernel aggregation predicts intellectual and social impairment in children born extremely preterm

BackgroundChildren born extremely preterm are at heightened risk for intellectual and social impairment, including Autism Spectrum Disorder (ASD). There is increasing evidence for a key role of the placenta in prenatal developmental programming, suggesting that the placenta may, in part, contribute to origins of neurodevelopmental outcomes.MethodsWe examined associations between placental transcriptomic and epigenomic profiles and assessed their ability to predict intellectual and social impairment at age 10 years in 379 children from the Extremely Low Gestational Age Newborn (ELGAN) cohort. Assessment of intellectual ability (IQ) and social function was completed with the Differential Ability Scales-II and Social Responsiveness Scale (SRS), respectively. Examining IQ and SRS allows for studying ASD risk beyond the diagnostic criteria, as IQ and SRS are continuous measures strongly correlated with ASD. Genome-wide mRNA, CpG methylation and miRNA were assayeds with the Illumina Hiseq 2500, HTG EdgeSeq miRNA Whole Transcriptome Assay, and Illumina EPIC/850 K array, respectively. We conducted genome-wide differential analyses of placental mRNA, miRNA, and CpG methylation data. These molecular features were then integrated for a predictive analysis of IQ and SRS outcomes using kernel aggregation regression. We lastly examined associations between ASD and the multi-omic-predicted component of IQ and SRS.ResultsGenes with important roles in neurodevelopment and placental tissue organization were associated with intellectual and social impairment. Kernel aggregations of placental multi-omics strongly predicted intellectual and social function, explaining approximately 8% and 12% of variance in SRS and IQ scores via cross-validation, respectively. Predicted in-sample SRS and IQ showed significant positive and negative associations with ASD case–control status.LimitationsThe ELGAN cohort comprises children born pre-term, and generalization may be affected by unmeasured confounders associated with low gestational age. We conducted external validation of predictive models, though the sample size (N = 49) and the scope of the available out-sample placental dataset are limited. Further validation of the models is merited.ConclusionsAggregating information from biomarkers within and among molecular data types improves prediction of complex traits like social and intellectual ability in children born extremely preterm, suggesting that traits within the placenta-brain axis may be omnigenic.

Non-pharmacological prevention and correction of cognitive disorders

This review deals with research on the effect of board games on the prevention of cognitive disorders in the older population. It is known that activities using board games significantly enhance educational and intellectual abilities in children. However, data on the effect of such interventions in older patients (including those at risk for developing dementia) are few and equivocal. In the Bronx Aging Study, reading, board games, playing musical instruments, and dancing were associated with a reduced risk of cognitive disorders. The MoVIES study assessed the cognitive status of 942 participants aged 65 years and older, and a lower risk of dementia was found in those who devoted more than 1 hour per day to 'recreational activities'. The French study of the PAQUID cohort showed that those who regularly played board games had a 15% lower risk of developing dementia than those who did not. This review attempts to systematize the known data (including functional MRI data) on how playing board games influences changes in cognitive function. The article covers memory mechanisms that are necessary components of cognitive health. Structures that are directly involved in long-term memory formation, especially explicit memory, including the hippocampus, parahippocampal gyrus, and entorhinal cortex, are described. The article includes studies covering not only geographical, economic and social status, age, gender, and level of cognitive load, but also the different assessments measuring the effect board games have on the brain. Different assessment methods and functional MRI data have demonstrated the potential effectiveness of using board games in the prevention of both age-related and pathological intellectual ageing.

The Effect of Music Intervention on Attention in Children: Experimental Evidence.

Although music has been utilized as a therapeutic tool for children with cognitive impairments, how it improves children’s cognitive function remains poorly understood. As a first step toward understanding music’s effectiveness and as a means of assessing cognitive function improvement, we focused on attention, which plays an important role in cognitive development, and examined the effect of a music intervention on children’s attention. Thirty-five children, aged 6 to 9 years, participated in this study, with data from 29 of the children being included in the analysis. A single 30-minute interactive music intervention was compared with a single 30-minute interactive video game intervention accompanied by computer-generated background music using a within-subjects repeated-measures design. Each intervention was implemented individually. Participants completed a standardized attention assessment, the Test of Everyday Attention for Children, before and after both interventions to assess changes in their attentional skills. The results indicated significant improvement in attention control/switching following the music intervention after controlling for the children’s intellectual abilities, while no such changes were observed following the video game intervention. This study provides the first evidence that music interventions may be more effective than video game interventions to improve attention control in children, and furthers our understanding of the importance of music interventions for children with attention control problems.

Evaluation of Pb concentrations in selected vegetables and portable drinking water, and intelligent quotients of school children in Ishiagu-a Pb mining community: health risk assessment using predictive modelling.

This study evaluates the concentrations of lead (Pb) in 6 selected vegetables and drinking water samples taken from an agricultural/mining town Ishiagu. This evaluation is important because these vegetables and water are major gateway of lead exposure through ingestion, especially children in the Pb mining environment. Pb at even very low concentrations has been shown to have adverse effect on developing brain and hence children's intellectual ability. The impact of lead-contaminated food/water intake on the cognitive function was focused on school children whose parents have lived in the Pb mining town for over 25years before they were born. Non-invasive, "target risk quotient" (TRQ) methodology, based on the principle of predictive toxicology was adopted for our analysis. Samples of these vegetables harvested in July and August 2015, and water taken from homes at 4 different villages in Ishiagu town and neighbouring community Akaeze (control), were subjected to appropriate chemical treatment/digestion procedures and the concentrations of Pb determined using AA-700 Shimadzu model atomic absorption spectrophotometer. From 642 structured questionnaire administered to the teachers/children, the daily vegetable ingestion rates for each vegetable (mg/child/day) and estimated daily intakes (EDI) of lead were obtained. The results show that the concentrations of Pb in water samples and the 6 vegetables harvested from the lead mining town vary as distances increase from the mining sites while the total target hazard quotients (TTHQs) for the vegetable crops were greater than one (˃1). The cognitive functions of 160 school children (aged 6-8years), sampled from 265 families based on their meeting the criteria for distances away from the mining site, were evaluated using Raven's Standard Progressive Matrices and psychometrics. The data generated were analysed using (SPSS) version 21.0 and results expressed as mean ± standard deviation of intelligent quotient (IQ). Students' t tests for independent samples were used to compare the IQ results for children in the lead mining area and non-mining area. A model based on predictive toxicology paradigm which can show a relationship between concentrations of lead in vegetables/water and cognitive function was developed. This model shows that there is a positive correlation between total lead concentrations in vegetables/water and children's cognitive function.

Psychological and pedagogical foundations for the development of critical thinking of students

The article is determined by the social order of society and the state for a creative, purposeful person with critical thinking, able to create new and transform existing ways of organizing educational activities. Modern educational programs provide a large amount of information for children, however, applying this knowledge is very problematic. Therefore, the application of critical thinking development technology allows the teacher to build a lesson in the form of group lessons, create an atmosphere of partnership in the classroom, and jointly find a solution to the problem. Thus, the use of this technology in the educational process ensures the productive development of the child's intellectual abilities.

Fluoride exposure from infant formula and child IQ in a Canadian birth cohort

BackgroundInfant consumption of formula reconstituted with fluoridated water can lead to excessive fluoride intake. We examined the association between fluoride exposure in infancy and intellectual ability in children who lived in fluoridated or non-fluoridated cities in Canada. MethodsWe examined 398 mother-child dyads in the Maternal-Infant Research on Environmental Chemicals cohort who reported drinking tap water. We estimated water fluoride concentration using municipal water reports. We used linear regression to analyze the association between fluoride exposure and IQ scores, measured by the Wechsler Primary and Preschool Scale of Intelligence-III at 3–4 years. We examined whether feeding status (breast-fed versus formula-fed) modified the impact of water fluoride and if fluoride exposure during fetal development attenuated this effect. A second model estimated the association between fluoride intake from formula and child IQ. ResultsThirty-eight percent of mother-child dyads lived in fluoridated communities. An increase of 0.5 mg/L in water fluoride concentration (approximately equaling the difference between fluoridated and non-fluoridated regions) corresponded to a 9.3- and 6.2-point decrement in Performance IQ among formula-fed (95% CI: −13.77, −4.76) and breast-fed children (95% CI: −10.45, −1.94). The association between water fluoride concentration and Performance IQ remained significant after controlling for fetal fluoride exposure among formula-fed (B = −7.93, 95% CI: −12.84, −3.01) and breastfed children (B = −6.30, 95% CI: −10.92, −1.68). A 0.5 mg increase in fluoride intake from infant formula corresponded to an 8.8-point decrement in Performance IQ (95% CI: −14.18, −3.34) and this association remained significant after controlling for fetal fluoride exposure (B = −7.62, 95% CI: −13.64, −1.60). ConclusionsExposure to increasing levels of fluoride in tap water was associated with diminished non-verbal intellectual abilities; the effect was more pronounced among formula-fed children.