Despite its greater extensiveness in comparison to the ferrying of their West African counterparts across the Atlantic Ocean into bondage in the New World, the history of the extraction of East Africans to serve as slaves in the various lands that ring the Indian Ocean is barely known to most of us. Particularly as Westerners, our knowledge of even the sketchiest outlines of the latter phenomenon pales before what we know intimately about the intricacies of the former. Furthermore, unknown altogether to too many is the fact that—from at least as early as the eighth century of the Common Era—these East African slaves were exported as distantly as China. Based principally on the pertinent Chinese sources, this study raises and investigates three fundamental questions concerning this conveyance of East Africans into China. First, who were the original enslavers of these East Africans and thus the prime purveyors of their entrance over the centuries into bondage in China? Second, how—that is, by land or by sea—and under what auspices were these East Africans typically transported from their homelands mainly along the eastern African coastline to a locale as far away as China? Third and finally, what was the probable fate of these East Africans once they had arrived in China? The essay concludes with a consideration of the consequentiality of this largely overlooked and therefore unheralded saga amidst the history of Chinese institutionalised servitude overall.

Heritability of age at menarche (AAM) in African populations remains largely unknown. A question on AAM was given to 1803 [454 monozygotic (MZ), 823 same-sex dizygotic (DZ), and 526 female members of opposite sex] adolescent twins attending public schools in Lagos State, Nigeria. The age range of the sample was 12–18 years, with a mean (SD) of 14.57 (±1.70) years. The data included 905 missing cases consisting of those who had not experienced menarche and did not recall AAM. Missing values were imputed using the Expectation-Maximization algorithm. Kaplan–Meier analysis based on the imputed data yielded 13.23 years [95% CI [13.18, 13.28] for the mean and 13.00 years [95% CI [12.96, 13.04] for the median of AAM. Twin correlation and model-fitting analyses were performed on the basis of those who reported AAM (MZ = 82 complete pairs and 38 cotwin missing cases; DZ = 157 complete pairs and 99 cotwin missing cases). Maximum likelihood MZ and DZ twin correlations for AAM were .63 (95% CI [.48, .74]) and .33 (95% CI [.19, .45]) respectively. Model-fitting analyses indicated that 58% (95% CI [46, 67]) of the variance of AAM was associated with additive genetic influences with the remaining variance, 42% (33−54) being due to nonshared environmental influences including measurement error. The heritability estimate found in this study was within the range of those found in Asian and Western twin samples.

Acapulco became a global town during the early seventeenth century, characterized not only by transpacific trade, but also by an increasingly large Afro-Mexican population residing and laboring at the port. A cohort of Afro-Mexican women gained prominence and visibility by delivering accurate predictions on the arrival of galleons to Acapulco. They adapted mixed African and Indigenous divination practices to calm port residents worried about galleon losses on the world's largest ocean. Scholarship on the Spanish Pacific has yet to investigate how the globalization of New Spain through galleon travel affected African and Afro-descendant communities. This article contends that the dangers of Pacific travel, and anxieties about them, frequently exceeded the therapeutic capacities of Catholic dogma. Black women, drawing on the profound West and West Central African estimation of female diviners, practiced clairvoyance to report on the location of galleons and whether they would arrive safely. The confluence of an increasing population of Afro-Mexicans with the economic dynamism of transpacific trade transformed spiritual life at the eastern node of Spain's Pacific empire. Black women positioned themselves at the center of these massive structural transformations and ultimately created new cultures as spiritual authorities in Acapulco.

There is a growing body of literature linking religious attendance to prosocial behavior (PB). The main purposes of the present study were to estimate genetic and environmental influences on the frequency of religious attendance (FRA) and to explore whether and how FRA moderates genetic and/or environmental influences on PB. As part of the Nigerian Twin and Sibling Study, 2860 (280 monozygotic male, 417 monozygotic female, 544 dizygotic male, 699 dizygotic female, and 920 opposite-sex dizygotic) twins (mean age = 14.2 years; SD = 1.7 years; age range = 12–18 years) completed a questionnaire regarding FRA and a PB scale. Similar to the findings from western twin samples, FRA showed substantial shared environmental influences of 74% (95% CI = 69%, 78%), with absence of genetic effects. The phenotypic correlation between FRA and PB was modest but positive and significant (r = .12; p < .01), suggesting that PB is higher among more frequent attenders than among less frequent attenders. The results of gene–environment (G × E) interaction model-fitting analysis revealed that FRA changed individual environmental experiences rather than genetic effects on PB such that while genetic variance was stable, non-shared environmental variance declined, leading the total phenotypic variance of PB to decrease with increasing levels of religious attendance.

The aim to this article is to analyse the judgments and opinions of Africans about Europeans during the early Portuguese expeditions to West Africa in the fifteenth and early sixteenth centuries. While opinions of Europeans about Africans are for that period certified by numerous and varied sources, the opinions of Africans are difficult to examine. Cultures of the West African coast in the fifteen and early sixteen century were illiterate. Local oral traditions do not go back – within the scope of this field of interest – to such distant centuries. There are two types of sources: Firstly, African statements written down in European texts, which require a particularly critical approach; secondly, some Africans expressed their opinions about Europeans in works of Art. These include the statues of Europeans from the area of present-day Sierra Leone (the Sapi people), and from the state of Benin (the Edo people). In this article the author examines: 1) the circumstances in which the Africans expressed their opinions (ad hoc meetings, political negotiations, trade, court ceremonies); 2) the authors (individuals or social and ethnic groups), which were attributed the judgments; 3) the content of speeches; and 4) the motives which guided the Africans. Then author compares individual cases, analyses the common characteristics and the distinct features of judgments and opinions known to us, and discusses the possibility of identification of general traits of Africans’ opinions about Europeans.

In low socio-economic status communities in South Africa, African men showed a low BMI. Data on the effect of low BMI on cardiovascular function are scant. The present study aimed to assess the associations between low BMI and markers of cardiovascular function such as pulse wave velocity (PWV) and blood pressure in Africans aged 35–65 years, with low socio-economic status. The study population (n 496) was stratified into a low-BMI group with BMI ≤ 20 kg/m2 and a normal-BMI group with BMI >20 kg/m2 and ≤ 25 kg/m2. Blood pressure (Omron HEM-757) and PWV (Complior SP; Artech-Medical) was determined. Africans with low BMI showed an increased arterial stiffness with significantly higher PWV compared with the normal-BMI group (men: P= 0·001; women: P= 0·026), which remained after adjustment. In men with low BMI, PWV correlated negatively with BMI before (r − 0·204; P= 0·012) and after (r − 0·200; P= 0·020) adjustment. Forward stepwise regression analyses indicated a negative association between PWV and BMI in African men. A J-curve was evident suggesting a detrimental effect of low BMI on cardiovascular function in Africans. A low BMI may contribute to the high prevalence of cardiovascular-related morbidity and mortality within a developing country.

Recent studies comparing cognitive abilities between contemporary twins and singletons in developed countries have suggested that twin deficits in cognitive abilities no longer exist. We examined cognitive abilities in a sample of twins and singletons born recently in Nigeria to determine whether recent findings can be replicated in developing countries. Our sample consisted of 413 pairs of twins and 280 singletons collected from over 45 public schools in Abuja and its neighboring states in Nigeria. The ages of twins and singletons ranged from 9 to 20 years with a mean (SD) of 14.6 years (2.2 years) for twins and 16.1 years (1.8 years) for singletons. Zygosity of the same-sex twins was determined by analysis of 16 deoxyribonucleic acid markers. We asked participants to complete a questionnaire booklet that included Standard Progressive Matrices-Plus Version (SPM+), Mill-Hill Vocabulary Scale (MHV), Family Assets Questionnaire, and demographic questions. The data were corrected for sex and age and then analyzed using maximum likelihood model-fitting analysis. Although twins and singletons were comparable in family social class indicators, singletons did better than twins across all the tests (d = 0.10 to 0.35). The average of d for SPM+ total [0.32; equivalent to 4.8 Intelligence Quotient (IQ) points] and d for MHV (0.24; equivalent to 3.6 IQ points) was 0.28 (equivalent to 4.2 IQ points), similar to the twin–singleton gap found in old cohorts in developed countries. We speculate that malnutrition, poor health, and educational systems in Nigeria may explain the persistence of twin deficits in cognitive abilities found in our sample.

Birth statistics for the Johannesburg Metropolitan Region were collected for 757 151 confinements from 1969 to 1989 (467 513 Black, 194 375 White, 67 250 Coloured and 28 013 Indian confinements). From 1969 to 1978 data on the sexes of twins were also collected for 375 203 of the confinements (203 504 Black, 129 631 White, 28 253 Coloured and 13 815 Indian confinements). A twin confinement was defined as two deliveries during one confinement. Twinning rates (TRs), defined as the number of twin confinements per 1000 total confinements, were calculated per year for each population group and from 1969–1978 estimates of the relative proportions of dizygotic (DZ) and monozygotic (MZ) twins were calculated and thus the relative DZTRs and MZTRs. A significant decline in Black and Coloured TRs was observed between 1969 and 1989. A significant decline in Black DZTR but not Black MZTR was observed between 1969 and 1978, the Coloured twin sample was too small to show significant trends over this period. It is probable that the overall decline in Black twinning may be explained by a decline in the DZTR. An analysis of birth statistics for 159 748 confinements (134 504 Black and 25 244 White confinements) collected as part of a prospective study of TRs in the Johannesburg Metropolitan Region from 1988 to 1990, indicated that the Black TR continued to decline at least until the end of 1990. TRs in the Johannesburg Metropolitan Region calculated from City Health Department birth statistics collected from 1988 to 1990 were: 13.8 and 10.77 for the Black and White populations, respectively. TRs for this period calculated from the combined birth statistics of 14 hospitals, nursing homes and maternity clinics across the region were: 12.4 and 10.88 for the Black and White populations, respectively.