Impact of culture on neurodevelopment

Résumé

The main objective of this doctoral thesis is to study the impact of cultural biases on neurodevelopment of children from the Arab world. For this purpose, the thesis is structured into eight chapters grouped into three general parts: an introduction part, an empirical part, and finally, a third part based on the discussion, concluding remarks, and future recommendations. The first part conceptualizes the term culture, how it interacts with cognition and the brain, and cross-cultural neuropsychology's history and current state (Chapter 1). Subsequently, Chapter 2 delves into the role of culture in child neurodevelopment, the cultural biases that may influence it, and the current status and importance of the study of non-Western populations, specifically the Arab world, for a better understanding of healthy and pathological child development. Finally, Chapter 3 presents the rationale and objectives of this thesis. The second part consists of three chapters for three scientific studies. Chapter 4 presents a review of cross-cultural neuropsychology using a machine learning technique to synthesize and classify the accumulated literature in the field, finding an excessive prominence of studies in the United States, English language, and American culture. Studies with the adult population appeared about three times more than studies with non-adults. Finally, 25 frequent topics in the field of cross-cultural neuropsychology were obtained, among which neuropsychological assessment, training and methodology, and the study of dementia stand out. In Chapter 5, cultural biases in the assessment of child intelligence are studied by applying a nonverbal and supposedly "culture-free" test (Raven's Coloured Progressive Matrices; CPM) to a sample of 7-, 9-, and 11-year-old Moroccan children with healthy development. The purpose of the study was to compare the participants' raw and transformed scores (ranks and IQ) using the norms from three non-representative countries: Spain, Oman, and the United Kingdom. Overall, these norms caused misclassification errors, with the worst results when applying the UK norms: 15.68% of participants fell into the "intellectual disability" range and 62.50% "below average." Transformed IQ was also biased, especially when using the UK norms at higher ages. In the third study, Chapter 6, a meta-analysis is conducted to study the intelligence development of children aged 6-11 years in the Arab world, as well as a comparison between raw and transformed scores to IQ using non-representative British WPC scales. While the meta-analysis and scores showed normal development, with intelligence scores positively related to age, the opposite effect was found when transforming these scores to IQ: while at age 6, IQ was around 100 points, it decreased with age to an IQ of 62 (more than two standard deviations below the mean, considered as a presumed "intellectual disability") at age 11. Finally, in the third part, the results are discussed with their consequent theoretical and practical (clinical and educational) implications in Chapter 7. Concluding remarks and future recommendations based on our findings are presented in Chapter 8.