African Samples Research Articles

Reduced Hippocampal Volumes Partially Mediate Effects of Prenatal Alcohol Exposure on Spatial Navigation on a Virtual Water Maze Task in Children

Prenatal alcohol exposure (PAE) has been linked to poorer performance on the Morris water maze (MWM), a test of spatial navigation in rodents that is dependent on hippocampal functioning. We recently confirmed these findings in children with PAE on a human analog of the MWM, the virtual water maze (VWM). Previous studies have shown that the hippocampus is particularly sensitive to PAE. Our aim was to determine whether hippocampal volume mediates the relation between PAE and virtual navigation. VWM and MRI hippocampal data were collected from 50 right-handed 10-year-old children in a heavily exposed Cape Town, South African sample. PAE data had been collected from their mothers during pregnancy, and the children were examined by expert fetal alcohol spectrum disorder (FASD) dysmorphologists. In the VWM, the participant attempts to learn the location of a hidden platform in a virtual pool of water across a series of learning trials using only distal room cues. Hippocampal volumes were derived using FreeSurfer from MRI scans administered within 1week of completing the VWM task. Both the fetal alcohol syndrome (FAS)/partial FAS and nonsyndromal heavy-exposed (HE) groups had smaller hippocampal volumes than controls. PAE was associated with reduced right hippocampal volumes even after control for total intracranial volume (ICV). Hippocampal volume was also positively associated with VWM performance. The relation between PAE and VWM performance was partially mediated by right hippocampal volume but not by total ICV. These data confirm previous reports linking PAE to poorer spatial navigation on the VWM and are the first to provide direct evidence that volume reductions in this region partially mediate the relation of FASD diagnosis to place learning, suggesting that PAE specifically impairs the ability to encode the spatial information necessary for successful location of the hidden platform on a navigation task.

Genetic diversity of 15 autosomal STRs in a sample of Berbers from Aurès region in the Northeast of Algeria and genetic relationships with other neighbouring samples

Background: The history of the Aurès mountains and neighbouring areas, a large region of the East of Algeria, was part of the history of the ancient independent Berber kingdoms supposed to be the ancestors of the current Berber people. The genetic background of this region has not yet been clarified.Aim: The aims of our study were to investigate the genetic characteristics of 15 autosomal short tandem repeats (STRs) in a sample from these regions, to determine the degree of heterogeneity among Algerian and North African samples and to analyse the genetic relationships with other populations.Subjects and methods: Allele frequencies, forensic parameters and Hardy–Weinberg equilibrium (HWE) of 15 autosomal STRs included in the PowerPlex® ESI 16 System were obtained from 308 individuals. Allele frequencies were used to determine the relationships with other populations.Results: All loci were highly polymorphic and no significant deviation from HWE was detected. Allele frequencies showed that the samples of Aurès region share genetic affinities with other Algerian, North African and Middle Eastern samples, with the exception of samples from Iran and Matmata.Conclusions: These markers revealed a genetic homogeneity between the Algerian and North African samples. The genetic affinities indicate that this sample could share a common ancestor with the Middle Eastern samples.

The Effect of Tobacco Smoking Differs across Indices of DNA Methylation-Based Aging in an African American Sample: DNA Methylation-Based Indices of Smoking Capture These Effects

Smoking is one of the leading preventable causes of morbidity and mortality worldwide, prompting interest in its association with DNA methylation-based measures of biological aging. Considerable progress has been made in developing DNA methylation-based measures that correspond to self-reported smoking status. In addition, assessment of DNA methylation-based aging has been expanded to better capture individual differences in risk for morbidity and mortality. Untested to date, however, is whether smoking is similarly related to older and newer indices of DNA methylation-based aging, and whether DNA methylation-based indices of smoking can be used in lieu of self-reported smoking to examine effects on DNA methylation-based aging measures. In the current investigation we examine mediation of the impact of self-reported cigarette consumption on accelerated, intrinsic DNA methylation-based aging using indices designed to predict chronological aging, phenotypic aging, and mortality risk, as well as a newly developed DNA methylation-based measure of telomere length. Using a sample of 500 African American middle aged smokers and non-smokers, we found that a) self-reported cigarette consumption was associated with accelerated intrinsic DNA methylation-based aging on some but not all DNA methylation-based aging indices, b) for those aging outcomes associated with self-reported cigarette consumption, DNA methylation-based indicators of smoking typically accounted for greater variance than did self-reported cigarette consumption, and c) self-reported cigarette consumption effects on DNA methylation-based aging indices typically were fully mediated by DNA methylation-based indicators of smoking (e.g., PACKYRS from GrimAge; or cg05575921 CpG site). Results suggest that when DNA methylation-based indices of smoking are substituted for self-reported assessments of smoking, they will typically fully reflect the varied impact of cigarette smoking on intrinsic, accelerated DNA methylation-based aging.

Genetic analysis provides insights into species distribution and population structure in East Atlantic horse mackerel (Trachurus trachurus and T. capensis).

Two sister species of horse mackerel (Trachurus trachurus and T. capensis) are described that are intensively harvested in East Atlantic waters. To address long‐standing uncertainties as to their respective geographical ranges, overlap and intraspecific population structure this study combined genetic (mitochondrial DNA and microsatellite) analysis and targeted sampling of the hitherto understudied West African coast. mtDNA revealed two reciprocally monophyletic clades corresponding to each species with interspecies nuclear differentiation supported by F ST values. The T. trachurus clade was found across the north‐east Atlantic down to Ghana but was absent from Angolan and South African samples. The T. capensis clade was found only in South Africa, Angola and a single Ghanaian individual. This pattern suggests that both species may overlap in the waters around Ghana. The potential for cryptic hybridization and/or indiscriminate harvesting of both species in the region is discussed. For T. capensis mtDNA supports high gene flow across the Benguela upwelling system, which fits with the species' ecology. The data add to evidence of a lack of significant genetic structure throughout the range of T. trachurus though the assumption of demographic panmixia is cautioned against. For both species, resolution of stock recruitment heterogeneity relevant to fishery management, as well as potential hybridization, will require more powerful genomic analyses.

Do minorities perceive procedural fairness merely in terms of ethnic bias suppression? Evaluation of the concept of fairness in multicultural conflicts

ABSTRACTThe present study investigated the impact of perceived procedural fairness enacted by societal actors on minority members’ willingness to accept decisions regarding multicultural issues. We particularly focused on ethnic bias suppression, which we expected to be highly salient in this type of conflict and deemed pivotal given its impact on the collective social self. Four studies (one cross-sectional study and three experiments) were conducted in African American minority samples. The results revealed that: (1) perceptions of procedural fairness cannot be reduced to solely evaluations of ethnic bias suppression, (2) the weight placed on bias suppression is indeed substantial, (3) procedural fairness and bias suppression each play a strong role in shaping minority members’ legitimacy perceptions of a decision-maker, and in turn, (4) decision acceptance. Theoretical and practical implications are discussed.

Assessing zygomatic shape and size for estimating sex and ancestry in a South African sample

Unidentified, decomposed and skeletonised human remains are frequently found in South Africa, therefore, standardised, reliable and relevant sex and ancestry estimation methods are required for forensic identification. This study assessed sex and ancestral variation in zygomatic size and shape in a South African population using geometric morphometric analyses. The zygoma of 158 South African individuals were sampled. Eight zygomatic landmarks were captured in 3-dimensions using a Microscribe G2 digitiser and assessed using procrustean geometric morphometrics. Shape and size differences were analysed using multivariate linear regression, discriminant function and canonical variate analyses. Males had significantly larger zygomas than females. Significant shape variation was found between ancestral groups. Bantu-speaking and Mixed ancestry individuals had narrower, shorter and more anteriorly projecting orbital margins, whilst Europeans had vertically elongated and receded orbital margins. European ancestral groups were most discernible from Bantu-speakers and Mixed ancestral groups. Ancestry estimation accuracies improved when ancestry was aggregated with sex. Pairwise ancestry-linked comparisons in females were as follows; Bantu-speakers (76%) from Europeans (72%), Bantu-speakers (71%) from Mixed ancestry (59%) and European (72%) from Mixed ancestry (63%). Similarly, ancestry-linked comparisons in males were as follows; Bantu-speakers (77%) from Europeans (81%), Bantu-speakers (53%) from Mixed ancestry (59%) and European (72%) from Mixed ancestry (82%). Size differences are putatively linked to variations in hormone-regulated growth and muscular robusticity between males and females. Shape variations between ancestral groups are likely attributable to the heterogenous genetic and ancestral origins of the South African population. It is challenging to distinguish between South Africa Bantu speakers and Mixed ancestry people due to Mixed ancestry individuals having variable genetic contributions from Khoesan, Bantu-speakers, Europeans and Asians. Bantu-speaking and Mixed ancestry people had zygomatic morphologies consistent with historical thermoregulatory adaptations to sub-Saharan climates, reported in African-descendants. Zygomatic morphology in European descendants suggests ancestral origins from colder climatic regions. This study demonstrated the utility of the zygoma in distinguishing between ancestral groups in South Africa, but further research is required to develop population-specific standards to distinguish between South African populations with shared African ancestry. The zygoma shows a promising ability to estimate sex and ancestry in South Africans, suggesting population specific standards for this bone may be of forensic interest.

RETRACTED ARTICLE: Insomnia, sleepiness, anxiety and depression among different types of gamers in African countries

Gaming has increasingly become a part of life in Africa. Currently, no data on gaming disorders or their association with mental disorders exist for African countries. This study for the first time investigated (1) the prevalence of insomnia, excessive daytime sleepiness, anxiety and depression among African gamers, (2) the association between these conditions and gamer types (i.e., non-problematic, engaged, problematic and addicted) and (3) the predictive power of socioeconomic markers (education, age, income, marital status, employment status) on these conditions. 10,566 people from 2 low- (Rwanda, Gabon), 6 lower-middle (Cameroon, Nigeria, Morocco, Tunisia, Senegal, Ivory Coast) and 1 upper-middle income countries (South Africa) completed online questionnaires containing validated measures on insomnia, sleepiness, anxiety, depression and gaming addiction. Results showed our sample of gamers (24 ± 2.8 yrs; 88.64% Male), 30% were addicted, 30% were problematic, 8% were engaged and 32% were non-problematic. Gaming significantly contributed to 86.9% of the variance in insomnia, 82.7% of the variance in daytime sleepiness and 82.3% of the variance in anxiety [p < 0.001]. This study establishes the prevalence of gaming, mood and sleep disorders, in a large African sample. Our results corroborate previous studies, reporting problematic and addicted gamers show poorer health outcomes compared with non-problematic gamers.

Exploring the Psychometric Properties of Two Primary Domains in the Revised Olweus Bully/Victim Questionnaire (R-OBVQ) among Primary School Learners in South Africa

This study examined the psychometric properties of two primary domains in the Revised Olweus Bully/Victim Questionnaire (R-OBVQ) in a convenience sample of 272 Grade 6 and 7 primary school learners in Gauteng, South Africa. This appears to be the first study to explore the psychometric properties of the self-report scale among a South African sample of primary school learners in Grade 6 and 7. An exploratory factor analysis (EFA) revealed that two distinct factors lay beneath the surface of the items tested (i.e., ‘being victimised’ and ‘bullying others’), and in combination explained 48.63% of the variance. Further results from the item analysis indicated that both factors were soundly reliable, yielding Cronbach Alpha values of .85 and .81, respectively. Notwithstanding the insight indicative in the results, the current study adopted only one technique to explore the factor solution in the data. As such, only modest support for the validity and reliability of the R-OBVQ is provided. Further research of the scale using (partial) confirmatory factor analysis among South African primary school learners is warranted.

Estimating Age of Mature Adults from Degeneration of the Medial End of the Clavicle in an African American Sample

Accurate age estimation is fundamental to identifying individuals in forensic anthropology and interpreting demographic patterns in bioarchaeology. Producing age estimates within useful ranges is particularly difficult when assessing older individuals (40+ years). Falys and Prangle (2015) developed a method (referred to henceforth as the FP method) for narrowing age-range estimates for older adults by scoring surface topography, porosity, and osteophytes of the medial end of the clavicle and applying regressions to create age-estimation ranges. That study included individuals of European decent aged 40+ years from four documented skeletal collections. New methods require testing for reproducibility as well as for the appropriateness and utility for subsamples from which the methods were not derived. Here we applied the FP method to a nineteenth-and twentieth-century African American age-and sex-documented skeletal sample (N = 229) from the Hamann-Todd Collection at the Cleveland Museum of Natural History. The method was reliable, and a statistically significant relationship was found between increased scores of degenerative features and older age. Accuracy in predicting age from the composite scores and regressions was 38.43–78.60% (compared to 96.4% from the original study). It failed to narrow age ranges beyond those available from other common aging methods (e.g., pubic symphysis, auricular surface of the ilium, sternal end of the fourth rib). Results suggest that differences in degeneration of articular surfaces are not negligible. This method should not be used universally across samples as a means of increasing accuracy of forensic identification. Sample-specific testing, in tandem with an exploration of variables that drive and/or affect age-related degeneration, should be pursued.

Factor structure of the CES-D in an impoverished African American sample

The Center of Epidemiological Studies Depression scale (CES-D) has been used for decades to identify symptomatology of depression in individuals. Overtime, the factor structure of the scale has been both confirmed and challenged when applied to different population samples. The present study explores the factor structure in population sample consisting of impoverished African American parents (N=1,020), and the data were collected from the Mobile Youth Study (MYS). Two-, four-, and higher-order models were used to identify the best fitting model. The results indicate that the most parsimonious model is a two-factor structure.

Maternal HIV status disclosure to young uninfected children: psychological variables of the mother

Mothers living with HIV are faced with the dilemma of when and how to disclose their HIV-positive status to their young uninfected children. In this study, a South African sample of mothers living with HIV, with young uninfected children (6–10 years) in the city of Tshwane was studied. In the sample of 406 mothers, 11.6% reported that they disclosed their HIV status to their young uninfected children. The research compared 47 mothers who disclosed (29 full disclosure and 18 partial disclosure) and a random sample of 50 mothers who did not disclose to their children, in terms of depression symptoms, parenting stress and coping strategies. The results showed that single and widowed mothers disclosed significantly more to their uninfected young children than mothers who had partners or were married. Mothers in the three disclosure groups did not differ in their experience of depression symptoms, parental distress and coping styles. Mothers who disclosed partially reported less parent–child dysfunctional interaction. Time since disclosure did not influence level of disclosure and was not significantly related to psychological outcome of mothers. Mothers who disclosed reported significantly more emotional and instrumental support as coping strategies than mothers who did not disclose. Mothers thus mostly disclose their status to their children to gain support and family closeness. Mothers who disclosed and had not disclosed did not differ in terms of psychological variables. Some mothers perceived partial disclosure as age-appropriate for young children. It is recommended that HIV-positive mothers receive psychosocial support services to equip them to disclose their health status in an age-appropriate way to their children, as it is documented that maternal disclosure benefits both mother and child.

Potential dual expansion of domesticated donkeys revealed by worldwide analysis on mitochondrial sequences.

Molecular studies on donkey mitochondrial sequences have clearly defined two distinct maternal lineages involved in domestication. However, domestication histories of these two lineages remain enigmatic. We therefore compared several population characteristics between these two lineages based on global sampling, which included 171 sequences obtained in this study (including Middle Asian, East Asian, and African samples) plus 536 published sequences (including European, Asian, and African samples). The two lineages were clearly separated from each other based on whole mitochondrial genomes and partial non-coding displacement loop (D-loop) sequences, respectively. The Clade I lineage experienced an increase in population size more than 8 000 years ago and shows a complex haplotype network. In contrast, the population size of the Clade II lineage has remained relatively constant, with a simpler haplotype network. Although the distribution of the two lineages was almost equal across the Eurasian mainland, they still presented discernible but complex geographic bias in most parts of Africa, which are known as their domestication sites. Donkeys from sub-Saharan Africa tended to descend from the Clade I lineage, whereas the Clade II lineage was dominant along the East and North coasts of Africa. Furthermore, the migration routes inferred from diversity decay suggested different expansion across China between the two lineages. Altogether, these differences indicated non-simultaneous domestication of the two lineages, which was possibly influenced by the response of pastoralists to the desertification of the Sahara and by the social expansion and trade of ancient humans in Northeast Africa, respectively.

TRADE STRUCTURE AND GROWTH: HOW DOES AFRICA FAIR AGAINST THE WORLD

We present a comparative analysis on the trade structure-growth nexus using two panel samples representing the top 10 trading African economies and the top 10 global trading economies covering the period 1995-2017. The findings from the pooled mean group estimators show disparities in the diversification/concentration-economic growth relationship between the two samples. On one hand, both diversification and concentration are found to be beneficial for short-run growth in the African sample but insignificant for the global sample. On the other hand, export concentration is harmful to long-run growth for the African sample but beneficial for long-run growth in the global sample. In further applying panel causality tests we only observe significant causal relations between export diversification/concentration and economic growth for the global sample and yet none are observed for the African sample and the policy implications of our findings are discussed.

The Infectious Diseases Preventive Health Behavior Scale (ID-PHBS): Development and Validation with an African Sample

Background: The World Health Organization (WHO) recommends preventive health behavior (PHB) as a sure means of preventing people from being infected with contagious diseases and curbing, for example, the current COVID-19 pandemic. This study aimed to develop the Infectious Diseases Preventive Health Behavior Scale (ID-PHBS) as an attempt to assess the level of adherence to the World Health Organization’s (WHO) COVID-19 protocols on social distancing, personal hygiene, wearing a face mask, and other precautionary practices. Methods: The ID-PHBS consists of twelve items, each rated on a 7-point Likert scale. The items were constructed based on the Protection Motivation Theory. The scale was developed and initially validated in a nationwide sample from Nigeria (N=703). Several psychometric tests were performed to establish its reliability and validity.Results: Confirmatory factor analysis (CFA) yielded one latent component. The internal consistency and Split-Half reliability were high and a moderate to strong positive correlation among participants’ scores on different items were recorded. The validity test showed that it had good construct validity and content validity. Conclusion: The ID-PHBS is a 12-point item scale, adjudged reliable and valid in assessing compliance with recommended preventive health protocols among the general population, and the items were designed such that it could be adapted for use during any future outbreak of infectious diseases.

Experimental study comparing burn healing effects of raw South African Shea butter and the samples from a Libyan market.

Background:The fat extracted from the nut of the African Shea tree (Vitellaria paradoxa) is called Shea butter. It has multiple uses at the local level as it is used in cosmetic products and as a cocoa butter substitute in chocolate industries. It has a high nutritious value and is also a valuable product on the local, national, and international markets, making it the ideal candidate to research and invest in. Aim:This study is a comparative experimental study of the possible burn healing effects between imported South African raw Shea butter and samples in a Libyan market.Method:The control samples were brought from South Africa (Benin traditional markets). A total of 18 different samples were collected from different sale centers in Tripoli, including pharmacies, beauty shops, and spices shops, in addition to one sample brought from Poland. Animal experiment on burn healing effect was carried out on nine male Sprague Dawley (350–400 g) rats aged 6–8 weeks old. After shaving the animal’s dorsum hair, a metal cube was used to create a deep second degree burn wound, and the cube was heated to 100°C for 20 seconds. Medication with Shea butter (control, T1, and T2) was initiated daily for one for these groups by the application of a thin film of the Shea butter samples on the burned areas. On days 1, 3, and 7, the rats were anesthetised and a sample from the burned scar tissue and skin adjacent were evaluated using pathological parameters.Results:The histological study indicates that the use of Shea butter T1 as topical treatment induces an immune response, which enhances the form of the presence of a large number of inflammatory cells in the epidermis and dermis layers. The treatment of burned skin with T2 lasted for 72 hours and it showed slightly significant healing in the normal structure of proliferative granulation tissue with accumulation of fibroblasts and inflammatory cells surrounding the sebaceous glands and hair follicles. Small areas of the epidermis which formed few layers were observed and some hair roots were grown. This was well seen in cases of T1 and T2. Shea butter bought as raw might have a bad effect on burned skin.Conclusion:Shea butter bought as raw might have bad effect on burned skin. On the other hand, the sample from Poland had a therapeutic effect, which was because of the additives such as avocado oil, grape seed oil, and others.

Demographic Predictors of Work Ethics in a South African Sample

Abstract Ethical behavior in South Africa, and consequently in the workplace, is currently a highly topical issue. Hence it was decided to investigate whether demographic differences exist regarding work ethics, in order to guide organizational decision-making and to understand work behavior in a South African sample. The sample consisted of 301 respondents, and data was collected using the Multidimensional Work Ethics Profile (MWEP), which was developed to measure seven facets of work ethics. Inferential statistical analysis was performed to analyze the dataset. The results indicate that male respondents scored higher on delay of gratification in comparison to their female counterparts. Test results for tenure found that increased years of service influenced respondents’ scores positively in hard work and delay of gratification.

Are We All Predictably Irrational? An Experimental Analysis

We examine the question of rationality, replicating two core experiments used to establish that people deviate from the rational actor model. Our analysis extends existing research to a developing country context. Based on our theoretical expectations, we test if respondents make decisions consistent with the rational actor framework. Experimental surveys were administered in Côte d’Ivoire and Ghana, two developing countries in West Africa, focusing on issues of risk aversion and framing. Findings indicate that respondents make decisions more consistent with the rational actor model than has been found in the developed world. Extending our analysis to test if the differences in responses are due to other demographic differences between the African samples and the United States, we replicated these experiments on a nationally representative analysis in the U.S., finding results primarily consistent with the seminal findings of irrationality. In the U.S. and Côte d’Ivoire, highly educated people make decisions that are less consistent with the rational model while low-income respondents make decisions more consistent with the rational model. The degree to which people are irrational thus is contextual, possibly western, and not nearly as universal as has been concluded.

Bullying and Suicide Ideation: Testing the Buffering Hypothesis of Social Support in a Sub-Saharan African Sample.

Substantial evidence indicates that adolescents and young adults have a disproportionately high incidence of most forms of violence, including suicide. Suicidality often includes suicidal ideation. The present study examined the relationship between bullying and suicidal ideation, and further tested whether social support moderates the association between the dimensions of bullying (verbal bullying, physical bullying, and bullying victimization) and suicidal ideation among adolescent secondary school students. A cross-sectional design was adopted for the study. Participants were 394 students (249 boys, 145 girls) drawn from two secondary schools in Nsukka semi-urban area, in southeast Nigeria. Participants completed the Illinois Bully Scale, the Columbia-Suicide Severity Rating Scale, and the Multidimensional Scale of Perceived Social Support (MSPSS). Hayes' regression-based PROCESS macro was used to analyze the data. Verbal bullying, physical bullying, and victimization were independently positively associated with suicidal ideation. Social support was not independently significantly associated with suicidal ideation, but it moderated the relationship between victimization and suicidal ideation. The positive relationship between victimization and suicidal ideation was strongest for adolescents who had low social support, compared to those who had moderate or high social support. This finding is consistent with the buffering hypothesis of social support, suggesting that supportive relationships for victims can mitigate suicidal ideation.

P.192 Predictors of treatment outcomes for refugees with posttraumatic stress disorder

The relationship between war-related trauma exposure, depressive symptoms and multiple risk behaviors among adolescents is less clear in sub-Saharan Africa.We analyzed data collected from a sample of school-going adolescents four years postwar. Participants completed interviews assessing various risk behaviors defined by the Youth Self Report (YSR) and a sexual risk behavior survey, and were screened for post-traumatic stress, anxiety and depression symptoms based on the Impact of Events Scale Revised (IESR) and Hopkins Symptom Checklist for Adolescents (HSCL-37A) respectively. Multivariate logistic regression was used to assess factors independently associated with multiple risk behaviors. The logistic regression model of Baron and Kenny (1986) was used to evaluate the mediating role of depression in the relationship between stressful war events and multiple risk behaviors.Of 551 participants, 139 (25%) reported multiple (three or more) risk behaviors in the past year. In the multivariate analyses, depression symptoms remained uniquely associated with multiple risk behavior after adjusting for potential confounders including socio-demographic characteristics, war-related trauma exposure variables, anxiety and post-traumatic stress symptoms. In mediation analysis, depression symptoms mediated the associations between stressful war events and multiple risk behaviors.The psychometric properties of the questionnaires used in this study are not well established in war affected African samples thus ethno cultural variation may decrease the validity of our measures.Adolescents with depression may be at a greater risk of increased engagement in multiple risk behaviors. Culturally sensitive and integrated interventions to treat and prevent depression among adolescents in post-conflict settings are urgently needed.

Pathways Between a Polygenic Score for Educational Attainment and Higher Educational Attainment in an African American Sample.

We investigated the extent to which performance on standardized achievement tests, executive function (EF), and aggression in childhood and adolescence accounted for the relationship between a polygenic score for educational attainment (EA PGS) and years of education in a community sample of African Americans. Participants (N = 402; 49.9% female) were initially recruited for an elementary school-based prevention trial in a Mid-Atlantic city and followed into adulthood. In first and twelfth grade, participants completed math and reading standardized tests and teachers reported on participants' aggression and EF, specifically impulsivity and concentration problems. At age 20, participants reported on their years of education and post-secondary degrees attained and their genotype was assayed from blood or buccal swabs. An EA PGS was created using results from a large-scale GWAS on EA. A higher EA PGS was associated with higher education indirectly via adolescent achievement. No other mediating mechanisms were significant. Adolescent academic achievement is thus one mechanism through which polygenic propensity for EA influences post-secondary education among urban, African American youth.