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"Reproductive Behavior"
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Ancient genomes show social and reproductive behavior of early Upper Paleolithic foragers
Present-day hunter-gatherers (HGs) live in multilevel social groups essential to sustain a population structure characterized by limited levels of within-band relatedness and inbreeding. When these wider social networks evolved among HGs is unknown. To investigate whether the contemporary HG strategy was already present in the Upper Paleolithic, we used complete genome sequences from Sunghir, a site dated to ~34,000 years before the present, containing multiple anatomically modern human individuals. We show that individuals at Sunghir derive from a population of small effective size, with limited kinship and levels of inbreeding similar to HG populations. Our findings suggest that Upper Paleolithic social organization was similar to that of living HGs, with limited relatedness within residential groups embedded in a larger mating network.
Journal Article
Trends in the age at reproductive transitions in the developing world: The role of education
Girls' school participation has expanded considerably in the developing world over the last few decades, a phenomenon expected to have substantial consequences for reproductive behaviour. Using Demographic and Health Survey data from 43 countries, this paper examines trends and differentials in the mean ages at three critical life-cycle events for young women: first sexual intercourse, first marriage, and first birth. We measure the extent to which trends in the timing of these events are driven either by the changing educational composition of populations or by changes in behaviour within education groups. Mean ages have risen over time in all regions for all three events, except age at first sex in Latin America and the Caribbean. Results from a decomposition exercise indicate that increases in educational attainment, rather than trends within education groups, are primarily responsible for the overall trends. Possible explanations for these findings are discussed.
Journal Article
Reproductive health and maternal sacrifice : women, choice and responsibility
\"This book demonstrates that the symbol of maternal sacrifice is the notion that 'proper' women put the welfare of children, whether born, in utero or not conceived, over and above any choices and desires of their own. The idea of maternal sacrifice acts as powerful signifier in judging women's behaviour that goes beyond necessary care for any children. The book traces its presence in various aspects of reproductive health, from contraception to breastfeeding. Pam Lowe shows how although nominally choices are presented to women around reproductive health, maternal sacrifice is used to discipline women into conforming to specific norms, reasserting traditional forms of womenhood. This has significant implications for women's autonomy. Women can resist or reject this disciplinary position when making reproductive decisions, but in doing so they may be positioned as transgressing and/or need to justify their decisions\"-- Back cover.
BOOK
Functions of galanin, spexin and kisspeptin in metabolism, mood and behaviour
The bioactive peptides galanin, spexin and kisspeptin have a common ancestral origin and their pathophysiological roles are increasingly the subject of investigation. Evidence suggests that these bioactive peptides play a role in the regulation of metabolism, pancreatic β-cell function, energy homeostasis, mood and behaviour in several species, including zebrafish, rodents and humans. Galanin signalling suppresses insulin secretion in animal models (but not in humans), is potently obesogenic and plays putative roles governing certain evolutionary behaviours and mood modulation. Spexin decreases insulin secretion and has potent anorectic, analgesic, anxiolytic and antidepressive-like effects in animal models. Kisspeptin modulates glucose-stimulated insulin secretion, food intake and/or energy expenditure in animal models and humans. Furthermore, kisspeptin is implicated in the control of reproductive behaviour in animals, modulation of human sexual and emotional brain processing, and has antidepressive and fear-suppressing effects. In addition, galanin-like peptide is a further member of the galaninergic family that plays emerging key roles in metabolism and behaviour. Therapeutic interventions targeting galanin, spexin and/or kisspeptin signalling pathways could therefore contribute to the treatment of conditions ranging from obesity to mood disorders. However, many gaps and controversies exist, which must be addressed before the therapeutic potential of these bioactive peptides can be established.The bioactive peptides galanin, spexin and kisspeptin have a common ancestral origin. This Review summarizes the available evidence on the role of these peptides in the regulation of metabolism, pancreatic β-cell function, energy homeostasis, mood and behaviour.
Journal Article
Exploring young women’s reproductive decision-making, agency and social norms in South African informal settlements
This paper explores reproductive decision-making among young women in South Africa's informal settlements and considers whether and how agency and social norm theory inform their decisions. Understanding whether, when and how young women make decisions about conception and motherhood is critical for supporting women to avoid unplanned, early motherhood. Qualitative data were collected from 15 young women in informal settlements in eThekwini, South Africa at three time points over 18 months, using in-depth interviews, participant observation and photovoice, and were analysed inductively. When the young women were teenagers and into their early twenties, and had not yet had a child, most paid little attention to whether or not they conceived. This shifted as they grew older and/or after having a first child, at which point many of the women began to express, and sometimes act upon, a greater desire to control whether and when they conceived and delay further pregnancies. At different times in their lives, both social norms and reproductive agency, specifically 'distributed agency' played significant roles in influencing their reproductive decision-making. Social norms held the most influence when they were teenagers and experiencing normative pressures to have a baby while young. As they grew older and/or had a first child they began to assert some agentic control around their reproduction. We therefore recommend that in order to improve the effectiveness of services and interventions supporting young women to delay unplanned pregnancies, programmers, researchers and policy makers must develop a better understanding of the role of social norms and agency at different stages of women's lives.
Journal Article
Predicting the effects of anthropogenic noise on fish reproduction
Aquatic animals use and produce sound for critical life functions, including reproduction. Anthropogenic noise is recognized as a global source of environmental pollution and adequate conservation and management strategies are urgently needed. It becomes therefore critical to identify the reproductive traits that render a species vulnerable to acoustic disturbances, and the types of anthropogenic noise that are most likely to impact reproduction. Here, we provide predictions about noise impact on fish reproduction following a two-step approach: first, we grouped documented effects of noise into three mechanistic categories: stress, masking and hearing-loss, and test which type of noise (continuous vs intermittent and regular vs irregular) was most likely to produce a significant response in each category with either a meta-analysis or a quantitative review, depending on data availability. Second, we reviewed existing literature to predict which reproductive traits would render fish most sensitive to stress, masking and hearing-loss. In step one, we concluded that continuous sounds with irregular amplitude and/or frequency-content (e.g. heavy ship traffic) were most likely to cause stress, and continuous sounds were also most likely to induce masking and hearing-loss. From step two we concluded that the vulnerability of a species to noise-induced stress will mainly depend on: (1) its potential to reallocate reproduction to more quiet times or locations, and (2) its vulnerability to masking and hearing-loss mainly on the function of sound communication in its reproductive behaviour. We discuss in which stages of reproduction fish are most likely to be vulnerable to anthropogenic noise based on these findings.Graphic abstract
Journal Article
Brazil’s Missing Infants
Zika virus epidemics have potential large-scale population effects. Controlled studies of mice and nonhuman primates indicate that Zika affects fecundity, raising concerns about miscarriage in human populations. In regions of Brazil, Zika risk peaked months before residents learned about the epidemic and its relation to congenital anomalies. This spatiotemporal variation supports analysis of both biological effects of Zika infection on fertility and the effects of learning about Zika risk on reproductive behavior. Causal inference techniques used with vital statistics indicate that the epidemic caused reductions in birth cohort size of approximately one-quarter 18 months after Zika infection risk peaked but 10 months after public health messages advocated childbearing delay. The evidence is consistent with small but not statistically detectable biological reductions in fecundity, as well as large strategic changes in reproductive behavior to temporally align childbearing with reduced risk to infant health. The behavioral effects are larger for more-educated and older women, which may reflect facilitated access to information and to family planning services within high-risk, mosquito-infested urban locations as well as perceptions about the opportunity costs of risks to pregnancy and infant survival.
Journal Article
Childlessness and its associated factors among Chinese women: a nationwide population-based study
Background
China has experienced a continuous decline in fertility rates, despite the end of the one-child policy, further intensifying population ageing. Timely evidence on the factors associated with childlessness among Chinese women is needed, alongside examining reproductive anxiety among childless women of reproductive age.
Methods
This nationwide, cross-sectional study was based on the 2023
Psychology and Behavior Investigation of Chinese Residents
Survey. A total of 10,802 women across mainland China who were (or had been) married were included, of whom 5,885 were of reproductive age (20–49 years) and 4,917 of post-reproductive age (≥ 50 years). Logistic and linear regression analyses were conducted to examine factors associated with childlessness among reproductive-aged and post-reproductive women, and reproductive anxiety among childless women of reproductive age at intrapersonal, interpersonal, and societal levels, as outlined in the social-ecological model.
Results
The comparison of reproductive patterns among women across different age groups showed a dramatic decline in the proportion of having three or more children, and a gradual increase in the childlessness over time. Among 5,885 women of reproductive age by the time of the survey, 612 (10.4%) reported having no children, while among 4,917 post-reproductive women, 161 (3.3%) were childless. Higher education level (OR = 2.83 [2.26, 3.55]; OR = 2.35 [1.44, 3.74]), being the only child in the family (OR = 2.85 [2.28, 3.55]; OR = 10.56 [7.38, 15.14]), and exposure to intimate partner violence (OR = 1.15 [1.02, 1.29]; OR = 1.68 [1.43, 1.98]) were significantly associated with childlessness among both reproductive-aged women and post-reproductive women. Poorer stress coping ability and exposure to sexual abuse during childhood were also associated with childlessness in post-reproductive women. Among childless women of reproductive age, higher education level, higher body image dissatisfaction, exposure to child abuse, parental issues during childhood, and belonging to ethnic minority groups were associated with increased reproductive anxiety.
Conclusions
This study used the most recent nationwide survey data from China to identify factors associated with childlessness and reproductive anxiety, with an emphasis on socio-economic factors and domestic violence. The findings highlight the significant impact of domestic violence on fertility behaviors and reproductive anxiety, providing valuable evidence for future policy interventions.
Journal Article