American Journal Of Human Biology[JOURNAL]
Sun
200 papers
Modeling of Maternal Factors Affecting Child Ever Born in Punjab, Pakistan: Indication From Multiple Indicator Cluster Survey (2017-2018).
Siddiqa M, Zubair A, Hanif A … +3 more , Iqbal S, Ashraf T, Ahmad S
Am J Hum Biol · 2026 Apr · PMID 41968963 · Full text
OBJECTIVE: Fertility trends and population dynamics in Pakistan significantly influence the nation's socioeconomic progress. Elevated fertility rates drive rapid population expansion, creating major challenges for the he...
OBJECTIVE: Fertility trends and population dynamics in Pakistan significantly influence the nation's socioeconomic progress. Elevated fertility rates drive rapid population expansion, creating major challenges for the healthcare system, education sector, and overall resource management. This study aims to identify key determinants influencing household fertility decisions among women aged 15-49 years in Punjab, Pakistan. METHODS: The number of children ever born to a woman is used as a proxy for household fertility. The analysis is based on data from the latest round of the Punjab Multiple Indicator Cluster Survey (MICS) 2017-2018. A Poisson regression model was employed to account for the count nature of the dependent variable. Both Poisson regression and logistic regression analyses were conducted to explore the most significant predictors of fertility variation across the province. RESULTS: Both the Poisson and logistic regression analyses identified a similar set of significant factors influencing fertility, including age, education, household wealth, fertility intentions, and delivery method. In both models, fertility increased progressively with advancing age, whereas higher educational attainment and better economic status were associated with reduced fertility and lower odds of having more than two children. Women who reported no desire for additional children exhibited higher fertility and a greater likelihood of higher parity in each model, while casarean delivery consistently showed a negative association with fertility outcomes. CONCLUSION: Fertility differentials across Punjab appear to be shaped by a combination of biological, socioeconomic, and maternal factors. The study highlights the influence of women's age, household wealth, desire for a child, educational attainment, and previous delivery methods on reproductive behavior. These findings carry important implications for fertility regulation strategies in high-fertility settings and suggest targeted interventions for promoting planned parenthood in similar socioeconomic contexts.
The 2D:4D Digit Ratio and Primary Sjögren's Syndrome: A Window Into Prenatal Hormonal Influences on Exocrine Autoimmunity.
Gür M, Akkoc RF, Oz B … +2 more , Karatas A, Koca SS
Am J Hum Biol · 2026 Apr · PMID 41958154 · Full text
OBJECTIVES: The pronounced female preponderance in Sjögren's syndrome (SS) points to a potential role for sex hormones in disease development. The ratio of the second to fourth digit (2D:4D), which serves as an indirect...
OBJECTIVES: The pronounced female preponderance in Sjögren's syndrome (SS) points to a potential role for sex hormones in disease development. The ratio of the second to fourth digit (2D:4D), which serves as an indirect marker of fetal androgen exposure, has shown associations with several immune-mediated conditions. The present study assessed whether 2D:4D ratios are lower in women diagnosed with SS relative to healthy individuals. METHODS: In this case-control investigation, 57 female SS patients (classified per the 2016 ACR/EULAR criteria) and 44 age-matched healthy women were recruited. The lengths of the index and ring fingers were measured on both hands with digital calipers, and digit ratios were derived. Group comparisons were conducted with Welch's t-test and supplemented by Mann-Whitney U-tests. RESULTS: Women with SS had lower 2D:4D ratios on both sides (right: 0.938 ± 0.030 vs. 1.011 ± 0.024, p < 0.001; left: 0.925 ± 0.034 vs. 1.009 ± 0.026, p < 0.001). The observed effect sizes were large (Cohen's d > 2.6). Lower ratios were driven predominantly by elongated ring fingers rather than shortened index fingers, a pattern compatible with heightened fetal androgen exposure. CONCLUSIONS: Women with primary SS exhibit lower 2D:4D digit ratios compared with healthy controls, suggesting that a shifted prenatal estrogen-to-androgen balance may prime the immune system toward the glandular autoimmunity and exocrine dysfunction that define this disease. These findings implicate the prenatal hormonal milieu as a potential contributor to the immunological processes underlying SS pathogenesis.
Recalled Adverse Childhood Experiences Predict Behavioral Traits Associated With an Accelerated Life History in Cebu, Philippines.
Carrera SC, Carba DB, Lee NR … +2 more , Gettler LT, Kuzawa CW
Am J Hum Biol · 2026 Apr · PMID 41948874 · Full text
OBJECTIVES: Adverse childhood experiences (ACEs) have long been associated with poor health in adulthood, with many researchers interpreting these findings as evidence of a "fast" life history. In this study we utilize d...
OBJECTIVES: Adverse childhood experiences (ACEs) have long been associated with poor health in adulthood, with many researchers interpreting these findings as evidence of a "fast" life history. In this study we utilize data from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) to test the expectations of this framework among inhabitants of the Cebu metropolitan area in the Philippines. METHODS: Data on development, behavior, and reproduction were collected from study participants (N = 1288, 54% male) over the course of multiple survey rounds, beginning before their birth in 1983-84. In 2018, participants completed a retrospective ACEs questionnaire. We built discrete hazard models and generalized linear models to test whether recalled ACEs predict characteristics of a "faster" life history in CLHNS. RESULTS: There was no significant relationship between ACEs and maturational timing, but individuals who recalled more ACEs engaged in health-risk behaviors earlier and exhibited younger ages at sexual debut. Among women specifically, ACEs also predicted a younger age at first reproduction and higher gravidity. After splitting ACEs into two dimensions, the same results were observed in response to deprivation but not threat. CONCLUSIONS: As in other low resource settings, physical maturation in Cebu was accelerated in households with greater access to resources but not in response to early psychosocial stressors as indicated by recalled ACEs. However, individuals who experienced ACEs did exhibit behavioral profiles consistent with faster life history scheduling and greater investment in reproduction.
Embodied Immunity: Place, Inequality, and Reproductive Outcomes in Two US Communities.
Manthey C, Gildner TE, Urlacher SS … +10 more , Mallott EK, Chaney C, Zhang A, Waimon S, Nemeth KL, Beauregard JA, Shing A, Samsonov A, Pfaff-Nash M, Cepon-Robins TJ
Am J Hum Biol · 2026 Apr · PMID 41937486 · Publisher ↗
Immune dysregulation has been linked to adverse reproductive outcomes, yet its biocultural determinants remain underexplored. This study examines how environmental inequality and embodied life history factors intersect t...
Immune dysregulation has been linked to adverse reproductive outcomes, yet its biocultural determinants remain underexplored. This study examines how environmental inequality and embodied life history factors intersect to shape pregnancy loss among women in two socio-environmentally distinct, low-resource US communities. We hypothesized that indicators of immune activation and reproductive history would be associated with increased likelihood of pregnancy loss. Data were collected from 112 women (ages 22-84) with prior pregnancies residing in rural Mississippi and periurban Illinois. Surveys captured demographic, health, and reproductive histories, and dried blood spot samples were analyzed for C-reactive protein (CRP), immunoglobulin E (IgE), and immunoglobulin G (IgG) concentrations. 32.6% of participants self-reported at least one pregnancy loss, with higher rates in Illinois than in Mississippi (41.2% vs. 22.0%). After excluding biomarker values suggestive of acute inflammation (> 10 mg/L CRP), none of the immune markers independently predicted pregnancy loss. As biomarkers were measured cross-sectionally, they are best interpreted as indicators of immune ecology, reflecting both current infections and exposures as well as long-term environmental inequality, rather than acute determinants of reproductive outcomes. In adjusted models, only number of pregnancies significantly predicted loss (p < 0.01). These findings suggest that pregnancy loss in this sample may be better explained by the cumulative embodiment of environmental and social conditions that are not being captured by isolated immune biomarkers.
Cortisol Stability at 16 and 30 Years in Urine Specimens Stored at -20°C.
Pan A, Saunders M, Holman DJ
Am J Hum Biol · 2026 Apr · PMID 41925080 · Full text
OBJECTIVE: This study aims to investigate whether urinary cortisol can be reliably measured after long-term storage at -20°C, using urine samples collected in 1993 from rural Bangladeshi women, and assayed after 16 and 3...
OBJECTIVE: This study aims to investigate whether urinary cortisol can be reliably measured after long-term storage at -20°C, using urine samples collected in 1993 from rural Bangladeshi women, and assayed after 16 and 30 years (2009 and 2023). METHODS: Specimens were collected by participants, placed in coolers with ice packs, transported to a field lab, and then refrigerated for up to 1 week before processing. Specific gravity was measured, and a 6.5 mL sample was archived at -20°C. Urinary cortisol was assayed in 2009 as part of a prior study using enzyme-linked immunosorbent assay (ELISA). In 2023, cortisol was measured in a subsample of 200 specimens using the same assay. RESULTS: Of the 200 specimens, 7 (3.5%) were measured with low precision. Cortisol could not be detected in nine specimens (4.5%). In the remaining 184 specimens, urinary log cortisol levels measured in 2009 and 2023 were positively correlated (r = 0.973, 95% CI: 0.964-0.980; p < 0.0001 and nonparametric r = 0.795; p < 0.0001). A paired t-test revealed a bias toward slightly greater values in the 2023 measurements (p < 0.0001). CONCLUSION: These results suggest that urinary cortisol remains largely intact and measurable in specimens stored at -20°C for three decades, and there is a strong correlation between cortisol measured after 16 and 30 years in storage.
Nurturing Bonds: A Qualitative Exploration of Breastfeeding and Responsive Feeding Practices in Samoan Mother-Infants Dyads.
Victoria B, Katherine D, Kemper L … +10 more , Lupesina V, Vaimoana F, Kima FS, Rafael PE, Amber HF, Take N, Christina SU, Jyothi A, Bribiescas RG, Hawley NL
Am J Hum Biol · 2026 Apr · PMID 41923391 · Full text
INTRODUCTION: Little is known about whether perceptions in Samoa of human milk composition and quality play a role in the decline in exclusive breastfeeding with age, the introduction of solid foods, or the degree to whi...
INTRODUCTION: Little is known about whether perceptions in Samoa of human milk composition and quality play a role in the decline in exclusive breastfeeding with age, the introduction of solid foods, or the degree to which mothers are utilizing responsive feeding practices. To explore this topic, we qualitatively explored feeding practices in Samoan families to identify areas in which the introduction of responsive feeding education may support and supplement the current breastfeeding promotion success. METHODS: In 2020-2021 we conducted one-on-one structured interviews with n = 100 mothers of infants aged 2-4 months. A subset of the sample (n = 25) was asked to take part in focus groups approximately a year later to gain further information regarding their overall infant feeding experience and behaviors, including breastfeeding and complementary feeding, related to responsive feeding methods and weaning. RESULTS: Three themes emerged from the interviews-Human Milk Contents, Nurturing Qualities and Hunger/Satiety Cues, while the focus groups generated seven themes-Human Milk Attitudes, Weaning Age, Weaning Foods, Introduction of New Foods, Mealtimes, Crying/Fussiness Response, and Sweet Food/Candy. While, to the best of our knowledge, responsive feeding practices are not taught in Samoa, some of the themes highlighted responsive feeding practices already being utilized in Samoan families. DISCUSSION AND CONCLUSION: The information gained from the interviews and focus groups can be used to develop evidence-based messaging that strives to educate parents and caregivers to successfully identify hunger and satiety signals in infants and encourage the introduction of healthy and age-appropriate foods that complement current Samoan breastfeeding practices and childhood dietary patterns.
Relationship Between Self-Reported Storytelling Ability and Reproductive Success Among Three Non-Western Populations in Nigeria, Pakistan, and Papua.
Fedurek P, Onyishi IE, Shah SIA … +4 more , Ayogu CK, Koziel S, Ugwu DC, Sorokowski P
Am J Hum Biol · 2026 Apr · PMID 41906204 · Publisher ↗
OBJECTIVES: Storytelling ability has been linked to social preference and reproductive success in egalitarian hunter-gatherer societies. However, whether storytelling confers similar reproductive benefits in more hierarc...
OBJECTIVES: Storytelling ability has been linked to social preference and reproductive success in egalitarian hunter-gatherer societies. However, whether storytelling confers similar reproductive benefits in more hierarchical societies remains unclear. This study examined the relationship between self-reported storytelling ability and reproductive success across three non-Western populations characterized by hierarchical social organization. METHODS: Data were collected from adult participants in Nigeria, Pakistan, and Papua (Indonesia). Self-reported storytelling ability was assessed using standardized measures. Reproductive success was indexed by number of children. Zero-inflated Poisson regression models were used to examine associations while controlling for age and sex. Sensitivity analyses were conducted in the Nigerian sample to assess the influence of high-parity individuals. RESULTS: In the Nigerian sample, storytelling ability was negatively associated with completed fertility in the count component of the model and negatively associated with the probability of childlessness in the zero-inflation component. Only the association with childlessness remained robust to additional covariates. No significant associations between storytelling ability and number of children were observed in the Pakistani or Papuan samples. CONCLUSIONS: The association between storytelling ability and reproductive success appears context-dependent and may differ between egalitarian and hierarchical societies. Findings suggest that storytelling ability may be more strongly related to the likelihood of parenthood than to completed fertility in certain socioecological settings.
In Utero Selection Echoes Across a Lifetime: Evidence From Historical Utah Populations.
Bruckner TA, Bonham J, Schacht R … +1 more , Smith KR
Am J Hum Biol · 2026 Mar · PMID 41876391 · Full text
OBJECTIVES: Past work in historical demography finds mixed evidence regarding the role of selective cohort mortality in utero in shaping that cohort's older-age mortality. Here we use, for the first time, high-quality in...
OBJECTIVES: Past work in historical demography finds mixed evidence regarding the role of selective cohort mortality in utero in shaping that cohort's older-age mortality. Here we use, for the first time, high-quality individual-level historical data to test whether adults from birth cohorts with a presumed high level of selection in utero show greater than expected older age survival. We examine a frontier population in Utah, born from 1850 to 1920 and followed to 2020, and use the annual cohort sex ratio (M:F) at birth, a marker of cohort selection in utero against males. METHODS: We performed Cox proportional hazards analyses (n = 201 542) to predict the hazard of older-age male mortality (i.e., > 50 years) and used a two-stage correction strategy to control for selective mortality before older age (i.e., before age 50). Analyses also control for strong temporal patterns in cohort survival and individual covariates including month of birth and religious affiliation. RESULTS: Consistent with our hypothesis, we find that males born to the least selected cohorts-as indicated by a high sex ratio at birth-show greater than expected hazard of older-age (i.e., > 50 years) mortality (p < 0.05). Interestingly, our exploration also shows a greater hazard of older-age mortality among females born to high sex ratio cohorts (p < 0.05). CONCLUSIONS: The sex ratio at birth in 19th and early 20th century cohorts gauges important demographic selection processes that appear detectable well into older age.
Women With Ovulatory Cycles Have Longer Sleep, but Phases of Their Menstrual Cycles Do Not Differ in Sleep Characteristics.
Wachowicz A, Galbarczyk A, Marcinkowska UM … +8 more , Ozdemir S, Klimek M, Tubek-Krokosz A, Słojewska K, Krzych-Miłkowska K, Mijas M, Ścibor M, Jasienska G
Am J Hum Biol · 2026 Mar · PMID 41876389 · Full text
OBJECTIVES: Duration and quality of sleep are influenced by many factors, including hormonal changes. The aim of this study was to investigate the differences between the phases of the menstrual cycle in total sleep dura...
OBJECTIVES: Duration and quality of sleep are influenced by many factors, including hormonal changes. The aim of this study was to investigate the differences between the phases of the menstrual cycle in total sleep duration and sleep stage distribution, specifically the duration of rapid eye movement (REM) phase, light, and deep sleep states and compare sleep parameters between ovulatory and anovulatory cycles. METHODS: The study involved 130 women aged 20-35 (mean = 26.2 years; SD = 4.14). Ovulation was detected using luteinizing hormone (LH) urine tests. Sleep data were collected using the Fitbit Alta HR trackers, which measured total sleep time and the duration of sleep stages. Sleep parameters were analyzed separately for each of the five phases: menstrual bleeding, follicular, periovulatory, luteal, and premenstrual using repeated measures ANOVA. Differences between ovulatory and anovulatory cycles were assessed using Student's t-test. RESULTS: Women with the ovulatory cycle slept longer and had longer REM phases compared to women without ovulation. No statistically significant differences were observed in total sleep duration or sleep stage distribution across five phases of the menstrual cycle among women with detected ovulation. CONCLUSION: The findings suggest that ovulatory status might be associated with differences in total sleep time and REM sleep duration, whereas sleep duration and sleep stage distribution across menstrual cycle phases remain relatively constant. These results suggest that the presence of ovulation, rather than phase-specific changes during the cycle, may play a more important role in shaping sleep characteristics.
The Relationship Between Biological Age and Emotional Intelligence in Young Swimmers.
Badzińska J, Żegleń M, Słowik J … +5 more , Bogusz W, Wądrzyk Ł, Sokołowski K, Strzała M, Kryst Ł
Am J Hum Biol · 2026 Mar · PMID 41873674 · Publisher ↗
OBJECTIVES: Emotional intelligence is crucial for young athletes, affecting their psychosocial well-being and performance. Biological development, which includes physiological changes, is also important for athletes, aff...
OBJECTIVES: Emotional intelligence is crucial for young athletes, affecting their psychosocial well-being and performance. Biological development, which includes physiological changes, is also important for athletes, affecting their physical abilities. This study aimed to analyze the relationship between biological age and emotional intelligence in young athletes. METHODS: The study group consisted of 65 young swimmers aged 12-14 from Kraków (Poland). The Popular Emotional Intelligence Questionnaire (PIKE) was used to assess emotional intelligence, and the study of biological age was conducted and calculated by an experienced anthropologist. Pearson correlation coefficients (r) were calculated to examine the relationship between variables. RESULTS: For girls, correlation analysis showed a significant relationship between biological age and the scale of accepting, expressing and using one's emotions in action. Statistical analysis also showed a significant correlation between calendar age and the scale of accepting, expressing and using one's own emotions in action for the entire sample. CONCLUSION: The study focused on analyzing the relationship between age, biological age and results on the Popular Emotional Intelligence Questionnaire (PIKE) in participants of different age groups. Key findings include significant correlations between age and emotional intelligence, particularly in the context of controlling one's own emotions (KON) and accepting, expressing and using one's emotions in action (AKC).
Urbanization, Physical Capacity, and Body Composition in Rarámuri and Mestizo Populations From Northern Mexico.
Lopez-Alonzo SJ, Martínez-Trevizo A, Islas-Guerra SA … +4 more , Orona-Escápite A, Gastelum-Cuadras G, Flores LA, Castillo LAE
Am J Hum Biol · 2026 Mar · PMID 41860192 · Publisher ↗
OBJECTIVES: To compare body composition and physical fitness indicators among non-urbanized rural Rarámuri (NURR), urbanized Rarámuri (UR), and urban Mestizo (MEST) populations, and to analyze the influence of urbanizati...
OBJECTIVES: To compare body composition and physical fitness indicators among non-urbanized rural Rarámuri (NURR), urbanized Rarámuri (UR), and urban Mestizo (MEST) populations, and to analyze the influence of urbanization on health-related physical performance. METHODS: A cross-sectional study was conducted in Chihuahua, Mexico (n = 171; 84 men, 87 women). Anthropometric and functional assessments followed the ISAK and YMCA protocols, which included BMI, waist circumference, body fat percentage, push-ups, sit-ups, flexibility, and aerobic capacity. Classifications were based on WHO and YMCA reference standards. Statistical differences were analyzed using the Kruskal-Wallis test (p < 0.05). RESULTS: Urbanization was associated with a progressive increase in adiposity and a decline in aerobic capacity. Participants from UR and MEST groups exhibited higher body weight, BMI, and body fat percentage compared to those in the NURR group (p < 0.05), as well as lower VOmax and functional endurance. Waist circumference revealed a greater distribution of metabolic risk among UR and MEST participants, while the NURR group maintained a leaner and metabolically efficient phenotype. CONCLUSIONS: The findings highlight a clear biocultural transition: as traditional physical activity patterns erode, physiological efficiency and cardiometabolic health deteriorate. The Rarámuri case exemplifies how urbanization induces functional regression rather than adaptation, underscoring the importance of preserving indigenous mobility and physical culture as key components of public health and cultural identity.
Reproductive Ecology and Evolutionary Anthropology: Foundations, Unanswered Questions, and Future Directions.
Bribiescas RG, Ellison PT
Am J Hum Biol · 2026 Mar · PMID 41858219 · Publisher ↗
The research field of reproductive ecology continues to be a major contributor to the scientific advancement of evolutionary anthropology and human biology in general. Primary contributions to human evolutionary biology...
The research field of reproductive ecology continues to be a major contributor to the scientific advancement of evolutionary anthropology and human biology in general. Primary contributions to human evolutionary biology include a greater understanding of the physiological mechanisms that manage lifetime reproductive effort, resource allocation, life history trade-offs, demographic variation in fertility, the adaptive traits that define humans (Homo sapiens), non-human primates, and our hominid ancestors as well as novel insights into reproductive health challenges such as cancer. Here we present a brief overview of the foundation on which this research path is based, including a summary of current research advances in human reproductive ecology, particularly within the scope of human variation. Future research directions, unanswered questions, and engagement with reproductive health challenges are discussed.
Distribution of Polymorphisms Associated With Obesity in a Sample of Admixed Mexican Adults.
Pérez LO, Ruderman A, Chacón-Duque JC … +10 more , Adhikari K, Bortolini MC, Acuña-Alonzo V, Canizales-Quinteros S, Gallo C, Poletti G, Rothhammer F, Rojas W, Ruiz-Linares A, González-José R
Am J Hum Biol · 2026 Mar · PMID 41858194 · Publisher ↗
OBJECTIVE: In Mexico, two-thirds of the adult population are overweight and almost a quarter are affected by obesity. These high obesity rates are primarily attributed to low-nutrient, high-calorie diets, reduced physica...
OBJECTIVE: In Mexico, two-thirds of the adult population are overweight and almost a quarter are affected by obesity. These high obesity rates are primarily attributed to low-nutrient, high-calorie diets, reduced physical activity, and to a certain extent, genetic factors. Most genetic variants for obesity risk have been identified through studies based predominantly on European populations. This study examines the roles of subcontinental ancestry, genetic polymorphisms, and socio-environmental factors in anthropometric measures within an admixed Mexican population. METHODS: We analyzed a sample of 1195 adult volunteers from the CANDELA consortium. Regression models were used to assess the influence of subcontinental Native American ancestries, socioeconomic level (education and SES), and genetic background on body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Polygenic risk scores (PRS) were constructed for each index using established alleles. RESULTS: An increase in obesity indices was significantly associated with a higher proportion of Native American ancestry, particularly waist-to-hip ratio. Polygenic risk scores were significantly associated with all indices, with BMI showing the highest risk. The effect of obesity scores was not influenced by ancestry on any of the evaluated indices, although the average frequency of risk alleles was slightly inversely correlated with higher Native American ancestry content. CONCLUSIONS: This study highlights the challenges of assessing genetic predisposition to complex disease in admixed populations, where numerous factors contribute to observed differences, emphasizing the need to consider regional genetic diversity in obesity research.
Admixture and Genetic Connectivity: Autosomal Insights Into Indo-Aryan Speakers at the Eastern Edge of the Indian Subcontinent.
Singh V, Basu Mallick C, Chatterjee M … +10 more , Tamang R, Desai S, Singh PP, Mishra RK, Pandey RK, Mishra R, Singh A, Suravajhala P, Bandyopadhyay AR, Chaubey G
Am J Hum Biol · 2026 Mar · PMID 41858098 · Publisher ↗
Assam serves as a melting pot where various ethnicities converge, shaped by its strategic location bordering the six northeastern states and neighboring countries. This study examines the genomic ancestry of Indo-Aryan s...
Assam serves as a melting pot where various ethnicities converge, shaped by its strategic location bordering the six northeastern states and neighboring countries. This study examines the genomic ancestry of Indo-Aryan speakers in Assam, a region at the eastern edge of the Indian subcontinent known for its diverse linguistic and cultural influences. Principal Components Analysis (PCA) revealed that Assamese Indo-Aryans cluster closely with Bangladeshi Indo-Aryans, diverging from the typical South Asian genetic continuum. This group shows significant ancestral influences from East and Southeast Asia. Outgroup f3 statistics indicated that Assamese Indo-Aryans exhibit greater genetic drift in relation to other Indo-Aryan populations, particularly the Harijan and Kol groups from the Ganga plain, rather than with geographically closer Bengali or Nyishi populations. Haplotype-based fine-structure and identity by descent (IBD) analyses confirmed a close genetic affinity with Bangladeshi Indo-Aryans, along with notable connections to Harijan and Kol populations. The low levels of Runs of Homozygosity (RoH) suggest a high degree of genetic diversity, most likely due to a result of admixture and a large effective population size. Admixture events are estimated to have occurred 55 to 61 generations ago, indicating a composition of 76% Indian ancestry and 24% East/Southeast Asian ancestry. These findings, with enhanced resolution, suggest a reconsideration of the previous assumption that Northeast India served as a genetic barrier. Instead, they appear to support its role as a corridor facilitating bidirectional gene flow between South and East/Southeast Asia. Furthermore, the coexistence of diverse linguistic affiliations of ethnic groups in this region reflects in their ancestry patterns. These findings highlight the complex interplay of geography, language, and genetic exchange in the region.
Determinants of Vitamin D in Indian Populations: Understanding the Interplay of Skin Pigmentation, Sun Exposure, and Genetic Variants.
Jonnalagadda M, Bhumkar S, Ozarkar S … +1 more , Ashma R
Am J Hum Biol · 2026 Mar · PMID 41858092 · Publisher ↗
OBJECTIVES: The present study evaluates the effects and interaction of skin pigmentation, sun exposure, and genetics on 25(OH)D levels among ostensibly healthy Indians. METHODS: Vitamin D was estimated (N = 427) and mean...
OBJECTIVES: The present study evaluates the effects and interaction of skin pigmentation, sun exposure, and genetics on 25(OH)D levels among ostensibly healthy Indians. METHODS: Vitamin D was estimated (N = 427) and means were compared between the sexes and study populations. Vitamin D was correlated with Melanin Index (MI) and Weekly Sun Exposure Scores (WSES) using Kendall's tau-b (τb). The effect of age, sex, MI, WSES, and 12 SNPs from vitamin D and skin pigmentation genes were tested on 25(OH)D levels using univariate and multivariate linear models. RESULTS: A total of 76.6% of the sample were deficient, with males being more deficient than females (p = 0.0016). Deshastha Brahmin caste with lowest MI (42.91 ± 4.47) and WSES (14.4 ± 8.55) reported highest 25(OH)D levels (26.09 ng/mL±16.84). Tribals with higher MI (52.83 ± 7.84-58.83 ± 6.37) and WSES (21.96 ± 7.85-28 ± 0) report low 25(OH)D levels (13.31 ± 7.05-17.94 ± 972). Vitamin D was weakly correlated with MI in Bhils and Kokanas (p < 0.05) and was not significantly correlated with WSES. Multivariate regression shows only sex (p = 0.031), MI (p = 0.018), and WSES (p < 0.001) to be significant predictors of vitamin D levels as compared to age, population, and rs1426654 genotype. CONCLUSION: Vitamin D levels vary significantly among populations with widespread deficiency seen in tribal and rural populations, suggesting population-specific environments and behavioral factors to be at play. Targeted dietary fortification is needed, and additional large-scale longitudinal and genome-wide association studies will help identify key factors responsible for vitamin D deficiency among Indian populations.
Polygyny and the Number of Children Ever Born in Afghanistan: The Moderating Role of Education-A Cross-Sectional Study.
Akbary MF, Rasa D, Saleem MU … +2 more , Khalid N, Jiang Q
Am J Hum Biol · 2026 Mar · PMID 41853953 · Publisher ↗
OBJECTIVE: This study aims to investigate the relationship between polygyny and the number of children ever born (CEB), as well as the moderating effects of education on this relationship in the context of Afghanistan. A...
OBJECTIVE: This study aims to investigate the relationship between polygyny and the number of children ever born (CEB), as well as the moderating effects of education on this relationship in the context of Afghanistan. Additionally, decomposition analysis of the marginal effect will be utilized to identify the factors that influence the likelihood of having a certain number of children. METHODS: A zero-inflated negative binomial (ZINB) regression model and marginal effect analysis were applied to the 2015 Afghanistan Demographic and Health Survey (AfDHS) with a sample (n = 29 461 women aged 15-49). CEB measured the number of children born to each woman; polygyny was assessed based on whether women were in polygynous or monogamous unions. All analyses were performed using STATA version 18.1. RESULTS: About 7% of the sample were in polygynous marriages, and the average number of children ever born (CEB) was 4.18. The ZINB model indicates that polygynous women had a 12% lower likelihood of higher CEB; when education was included as a moderator, this reduction increased to 13%. The marginal effects further show that polygynous women had, on average, 0.54 fewer children than monogamous women. Education also demonstrated a protective effect: primary education was associated with 0.17 fewer children, while higher education reduced the number of children by 0.58. CONCLUSION: This study indicates that decreases in CEB among women in both polygynous and monogamous unions are linked to higher levels of women's education and delayed marriage. The study concludes that increasing access to family planning and promoting women's education may reduce the disparities in CEB between polygyny and monogamy in Afghanistan.
The First Allometric Analysis in Newborns Rejects the Allometry Hypothesis for 2D:4D: Strong Developmental Evidence for Prenatal Hormonal Programming.
Özener B, Ertuğrul B, Aksoy G
Am J Hum Biol · 2026 Mar · PMID 41845962 · Publisher ↗
Abstract loading — click title to view on PubMed.
Exploration of Household Socioeconomic Factors Related to Fertility and Child Mortality in Pakistan.
Ibupoto MH, Ashraf MB, Qiu X … +3 more , Yankui S, Laghari AA, Sang A
Am J Hum Biol · 2026 Mar · PMID 41834437 · Publisher ↗
INTRODUCTION: Fertility and child mortality remain critical public health and development concerns in Pakistan, reflecting deep-rooted socioeconomic disparities at the household level. This narrative review synthesizes e...
INTRODUCTION: Fertility and child mortality remain critical public health and development concerns in Pakistan, reflecting deep-rooted socioeconomic disparities at the household level. This narrative review synthesizes empirical evidence on patterns of child fertility and mortality and examines the socioeconomic, demographic, and contextual factors shaping these outcomes in Pakistan. METHODS: A design to synthesize empirical evidence on the following established narrative review guidelines, peer-reviewed studies published over the past two decades were identified through major academic databases, including those focusing on fertility behavior, child survival, and household-level determinants. FINDING: Gender norms, son preference, and women's autonomy also emerge as significant contributors influencing reproductive decision-making and child health outcomes. Furthermore, regional inequalities and limited utilization of maternal and child healthcare services exacerbate risks among socioeconomically disadvantaged households. The findings underscore the interconnected nature of fertility behavior and child survival within broader structural and sociocultural contexts. The reviewed literature consistently demonstrates that child mortality and child fertility rates are strongly associated with household socioeconomic conditions, particularly parental education, household wealth status, maternal employment, place of residence, and access to health services. CONCLUSION: This review highlights the need for integrated policy interventions that address socioeconomic inequalities, strengthen maternal and child health systems, and promote female education and empowerment to achieve sustained improvements in child survival and fertility regulation in Pakistan.
Nutrition and Handgrip Strength Among Adults in Rural Matlab, Bangladesh.
Naik G, Durney V, Gray E … +11 more , Labossiere J, Sanchez L, Seafuse J, Kumar A, Haque F, Blumenfield T, Cully S, Alam N, Raqib R, Wander K, Shenk MK
Am J Hum Biol · 2026 Mar · PMID 41834426 · Full text
OBJECTIVE: Handgrip strength (HGS) provides a dynamic indicator of overall strength and physical fitness. Population-based investigations of anemia and iron deficiency as predictors of HGS are limited; most studies rely...
OBJECTIVE: Handgrip strength (HGS) provides a dynamic indicator of overall strength and physical fitness. Population-based investigations of anemia and iron deficiency as predictors of HGS are limited; most studies rely on elderly and/or clinical samples. We assessed iron deficiency, anemia, body mass index (BMI), and body fat percentage as predictors of HGS among a representative cross-sectional sample of adult residents of Matlab, Bangladesh. METHODS: We collected HGS, anthropometric measurements, and whole blood specimens from a representative, population-based sample of adults in Matlab. We used hemoglobin to identify anemia and soluble transferrin receptor to identify iron deficiency. We estimated mixed-effects generalized linear models of HGS. RESULTS: Iron deficiency, but not anemia, was negatively associated with HGS among both men and women. Among men, but not women, underweight BMI was negatively associated with HGS, and overweight BMI was positively associated with HGS. CONCLUSIONS: Iron nutrition is important for muscles' capacity for work and overall physical fitness, regardless of the presence of anemia. Among men (but not women) in this setting, BMI categories seem to capture differences in muscle tissue as well as adiposity.
Fifty Years of Research From the Human Biology Association.
Leonard WR
Am J Hum Biol · 2026 Mar · PMID 41834076 · Publisher ↗
Abstract loading — click title to view on PubMed.
About
- Frequency
- Sun
- Papers found
- 200
- RSS feed
- Subscribe