Grandmotherhood is associated with reduced OXTR DNA methylation.

In mammals, both parental and alloparental care are associated with increased brain oxytocin signaling. Grandmothers are important alloparents in many human families. Based on animal model research showing that peripheral Oxtr methylation is associated with Oxtr expression in the nucleus accumbens, we investigated whether grandmaternal caregiving is associated with lower peripheral OXTR methylation. Results reveal several regions within OXTR where grandmothers have lower DNA methylation compared with non-grandmother controls, and no regions where grandmothers have higher OXTR DNA methylation. Among grandmothers, OXTR methylation was most strongly correlated with the grandmother's assessment of the degree of positive feelings between her and the grandchild, which in turn predicted caregiving engagement. Although there was little evidence that grandmaternal OXTR methylation modulated grandmaternal neural responses to viewing photos of the grandchild within brain regions involved in caregiving motivation, it was negatively correlated with the neural response to an unknown grandchild. Thus, while OT signaling may not be essential for activating grandmaternal brain reward systems in our low-stress experimental context, it may support caregiving motivation towards unrelated children. Future longitudinal research should determine whether the transition to grandmotherhood is associated with a reduction in OXTR methylation.

Grandmother-grandchild physiological synchrony in Chinese three-generation families: Links with child emotion regulation.

The current study examined the characteristics of physiological synchrony between grandmothers and grandchildren in Chinese three-generation families, and the associations between physiological synchrony and child emotion regulation. The participants included 92 children (age 8-10-year old) and their grandmothers. Respiratory sinus arrhythmia (RSA) was collected from both grandmothers and their grandchildren throughout a collaborative drawing task and a conflict discussion task. Child emotion regulation was measured using the Children's Emotional Management Scale. We found no evidence for an overall pattern of concordant or discordant synchrony within dyads. Instead, there was great variability in patterns of synchrony across dyads. During the collaborative drawing task, concordance in grandmother's RSA and grandchildren's subsequent RSA was linked with better emotion regulation. During the conflict discussion, concordance in grandmother's RSA and grandchildren's simultaneous RSA was linked with poorer emotion regulation. These results suggest that grandmother-grandchild synchrony in different directions, time lags, and contexts has different influences on children's emotion regulation. The findings of this study highlight the importance of contextual physiological co-regulation between Chinese children and their grandmothers for children's social-emotional development.

Selectively advantageous instability in biotic and pre-biotic systems and implications for evolution and aging.

Rules of biology typically involve conservation of resources. For example, common patterns such as hexagons and logarithmic spirals require minimal materials, and scaling laws involve conservation of energy. Here a relationship with the opposite theme is discussed, which is the selectively advantageous instability (SAI) of one or more components of a replicating system, such as the cell. By increasing the complexity of the system, SAI can have benefits in addition to the generation of energy or the mobilization of building blocks. SAI involves a potential cost to the replicating system for the materials and/or energy required to create the unstable component, and in some cases, the energy required for its active degradation. SAI is well-studied in cells. Short-lived transcription and signaling factors enable a rapid response to a changing environment, and turnover is critical for replacement of damaged macromolecules. The minimal gene set for a viable cell includes proteases and a nuclease, suggesting SAI is essential for life. SAI promotes genetic diversity in several ways. Toxin/antitoxin systems promote maintenance of genes, and SAI of mitochondria facilitates uniparental transmission. By creating two distinct states, subject to different selective pressures, SAI can maintain genetic diversity. SAI of components of synthetic replicators favors replicator cycling, promoting emergence of replicators with increased complexity. Both classical and recent computer modeling of replicators reveals SAI. SAI may be involved at additional levels of biological organization. In summary, SAI promotes replicator genetic diversity and reproductive fitness, and may promote aging through loss of resources and maintenance of deleterious alleles.

Healthy Outcomes through Peer Educators: Feasibility of a peer support diabetes prevention programme for African-American grandmother caregivers.

AIM: To assess the protocol feasibility and intervention acceptability of a community-based, peer support diabetes prevention programme (DPP) for African-American (AA) grandmother caregivers at risk for diabetes. MATERIALS AND METHODS: Grandmother caregivers were randomized in a 2:1 ratio to DPP (active comparator) or DPP plus HOPE (Healthy Outcomes through Peer Educators; intervention). DPP + HOPE incorporated support from a peer educator who met with participants in person or by telephone every week during the 1-year intervention. Outcomes included: (1) recruitment rates, outcome assessment, and participation adherence rates assessed quantitatively; and (2) acceptability of the programme assessed through end-of-programme focus groups. RESULTS: We successfully consented and enrolled 78% (n = 35) of the 45 AA grandmothers screened for eligibility. Eighty percent of participants (aged 64.4 ± 5.7 years) were retained up to Week 48 (74% for DPP [n = 17] and 92% for DPP + HOPE [n = 11]). All grandmothers identified social support, neighbourhood safety, and access to grocery stores as influences on their health behaviours. At Month 12, the active comparator (DPP) group and the intervention group (DPP + HOPE) had a mean change in body weight from baseline of -3.5 ± 5.5 (-0.68, -6.29) kg and - 4.4 ± 5.7 (-0.59, -8.2) kg, respectively. CONCLUSIONS: This viable study met the aim of educating and equipping AA grandmothers with the practical and sustained support needed to work toward better health for themselves and their grandchildren, who may be at risk for diabetes. The intervention was both feasible and acceptable to participating grandmothers and their organizations.

Grandmother effects over the Finnish demographic transition.

Demographic transitions are defining events for human societies, marking shifts from natural mortality and fertility rates to the low rates seen in industrialised populations. These transitions can affect trait evolution through altering the direction and strength of selection when variance in fertility and mortality decline. One key feature of human evolution is the evolution of extended post-reproductive life through indirect fitness benefits from grandmothering. Although studies in pre- and post-transition societies have documented beneficial grandmother presence, it remains unknown whether these associations changed before, during, or after the transition. Here, we use genealogical data from eighteenth- to twientieth-century Finland to show grandmother-associated changes of two measures of evolutionary fitness (grandchild survival and birth rate) over the transition. We find that grandmothers had greater opportunity to help as the transition progressed, but their effect on grandchild survival declined alongside general mortality rates, implying that selection on lifespan from grandmothering declined too. Whilst grandmother presence was still associated with reduced birth intervals and hence more grandchildren born post-transition, the nature of this relationship changed greatly. This suggests that although potential for intergenerational interactions increased over the demographic transition, the (hypothesised) evolutionary importance of these interactions declined, which reduced selection for extended post-reproductive lifespan.

Grandmaternal body mass index in early pregnancy and risk of grandoffspring stillbirth: A nationwide, three-generation cohort study.

We investigated the association between maternal grandmaternal early pregnancy body mass index (BMI) and grandoffspring stillbirth risk in a Swedish population-based three-generation cohort of 176,908 grandmothers (F0), 197,579 mothers (F1), and 316,459 grandoffspring (F2) born 1997-2016. There were 998 stillbirths (risk, 3.2 per 1000 births). Compared with grandmaternal BMI 18.5-24.9, adjusted relative risks [RR (95% CI)] of grandoffspring stillbirth for BMI 25.0-29.9 and ≥30 were, respectively, 1.41 (1.15, 1.72) and 1.62 (1.14, 2.30). RR (95% CI) for corresponding maternal (F1) BMI categories were, respectively, 1.32 (1.06, 1.65) and 1.77 (1.39, 2.25). Maternal BMI mediated only 19% of this relation. Grandmaternal preeclampsia and maternal small-for-gestational age (SGA) birth were related to increased F2 stillbirth risk but did not mediate the association between grandmaternal BMI and grandoffspring stillbirth risk. To explore whether this association was explained by factors shared within families, we studied the relation of maternal full sisters' BMI and stillbirth risk in 101,368 pregnancies. Stillbirth RR (95% CI) for full sisters' BMI 25.0-29.9 and ≥30 compared with 18.5-24.9 were, respectively, 0.76 (0.51, 1.13) and 0.88 (0.55, 1.40). In conclusion, grandmaternal overweight and obesity are associated with grandoffspring stillbirth. This association is not fully explained by shared familial factors.

A history of asthma may be associated with grandparents' exposures to stress and cigarette smoking.

Introduction: Within human epidemiological studies, associations have been demonstrated between grandparental exposures during childhood and grandchildren's outcomes. A few studies have assessed whether asthma has ancestral associations with exposure to cigarette smoking, but results have been mixed so far. Material and methods: In this study we used four generations: (F0 great-grandparents, F1 grandparents, F2 parents, F3 study children) of the Avon Longitudinal Study of Parents and Children (ALSPAC) to determine whether there is evidence of associations between asthma in generations F2 or F3 and exposures to severe trauma in childhood and/or active cigarette smoking during the adolescence of grandmothers and grandfathers in generations F0 and F1 respectively, or of a history of a F0 or F1 grandmother smoking during pregnancy. Results: We have shown that: a) stress exemplified by the death of a F1 grandparent's parent during the grandparents' childhood was associated with increased risk of asthma in generation F3, especially if the grandparent involved was the paternal grandmother; b) if the grandparents of generations F0 or F1 smoked during adolescence (i.e. < 17 years), their grandchildren in generations F2 and F3 were more likely to have a history of asthma; c) paternal F1 grandmother's smoking in pregnancy was associated with her F3 grandchild's asthma at age 7; d) There were differences between the results for the grandsons and granddaughters of the paternal grandmother with exposure to smoking in adolescence and with smoking in pregnancy. e) The addition of all of the individual exposure variables to the different analyses often provided a considerable increase in goodness of fit compared with only adding demographic factors associated with asthma at P < 0.10 such as social class; this was particularly true when all four exposure variables were combined in one model, suggesting possible synergistic effects between them. Discussion: We have shown associations between all four types of exposure to the grandparents to be associated with asthma in the grandchildren, such that the results both depended on whether the male or female line was involved, and the sex of the grandchildren. It was notable that the paternal grandmother was particularly involved in many of the associations. We emphasize that these are exploratory analyses, that asthma diagnostic criteria likely changed over time and may not be consistent between generations, and that the results should be tested in other cohorts.

Impact of kinship support on child mortality in the Upper East Region of Ghana: assessing the Grandmother Hypothesis.

BACKGROUND: The grandmother is an important kin member whose contribution to childcare and survival has been recognized in the literature, hence the Grandmother Hypothesis. This article examines the effect of the presence of a grandmother on child mortality. METHODS: Data were obtained from the Navrongo Health and Demographic Surveillance System, located in the Upper East Region of Ghana. Children born between January 1999 and December 2018 were included in the analysis. Person-months lived for each child were generated. The multilevel Poisson regression technique was employed to investigate the effect of a grandmother on child survival. RESULTS: In all, 57 116 children were included in the analysis, of which 7% died before age 5 y. Person-months were generated for the children, which produced 2.7 million records, with about 487 800 person-years. After controlling for confounders, results showed that children in households with paternal grandmothers are 11% less likely to die compared with those without paternal grandmothers. However, when other confounders were taken into accounts, the beneficial effect of maternal grandmothers disappeared. CONCLUSIONS: We conclude that the presence of grandmothers improves child survival, thus sustaining the Grandmother Hypothesis. The experiences of these grandmothers should be tapped to improve child survival, particularly in rural areas.

Grandparental co-residence and grandchild survival: the role of resource competition in a pre-industrial population.

Although grandparents are and have been important alloparents to their grandchildren, they are not necessarily only beneficial but can also compete with grandchildren over limited resources. Competition over parental care or other resources may exist especially if grandparents live in the same household with grandchildren and it can be dependent on grandchild age. By utilizing demographic data collected from historic population registers in Finland between 1761 and 1895 (study sample n = 4041) we investigate whether grandparents living in the same household with grandchildren are detrimental or beneficial for grandchild survival. Having a living but not co-residing grandmother or grandfather were both associated with better survival whereas having a co-resident grandfather was associated with lower chance to survive for infants (age < 1 year). Separating the effect between maternal and paternal grandparents and grandmothers and grandfathers revealed no differences in the effects between lineages. Negative effect of having a co-residing grandfather was not significant when grandfathers were separated for lineage specific models. These results implicate that accounting for the co-residence status and child's age, grandparents were mostly beneficial when not co-residing with very young children and that having a co-residing grandfather at that age could be associated with lower chances to survive. Predictions made by grandmother hypothesis and resource competition both received support. The results presented here also offered comparison points to preindustrial and contemporary three-generational families.

A comparative study of the effects of Kangaroo care by mothers and maternal grandmothers on the vital signs of hospitalized preterm newborns: a randomized controlled clinical trial study.

BACKGROUND: Kangaroo care (KC) is an effective technique to prevent injury in newborns due to prematurity and hospitalization. Mothers of preterm newborns experience their own set of physical and mental problems. Such circumstances call for another family member to take care of the newborn. This study compared the effect of KC by mothers and maternal grandmothers on the vital signs of preterm newborns. METHODS: This parallel randomized controlled trial was done at the neonatal and NICU departments of the hospital in Kuhdasht in Iran. Eighty preterm neonates were selected through convenience sampling according to the eligibility criteria, then by stratified block randomization allocated to two groups. The control group received KC from the mother, and the intervention group received KC from the maternal grandmothers on the vital signs of preterm newborns. Vital signs were assessed 15 min before, during, and after the KC as the primary outcome. The data collection tools included a demographic questionnaire and a form to record the vital signs. Vital signs were measured by a pulse oximeter, an electronic thermometer, and observation. Data were analyzed by the chi-square test, the independent t-test, and the repeated measures ANOVA. RESULTS: The vital signs of newborns in each group showed a significant difference before, during, and after receiving KC (P < 0.05). Nevertheless, the vital signs of the newborns did not differ significantly between the mother and the maternal grandmother KC groups (P > 0.05). CONCLUSION: KC by maternal grandmother may stabilize the vital signs of preterm newborns as much as when this type of care is provided by the mother. We, therefore, recommend the provision of KC by the maternal grandmother, as a support and substitute for the mother whenever she is incapable of being at the hospital and to enable the mother to rest. TRIAL REGISTRATION: Iranian Registry of Clinical Trials IRCT20211225053516N1, March 31, 2022.

Sparse ensemble neural code for a complete vocal repertoire.

The categorization of animal vocalizations into distinct behaviorally relevant groups for communication is an essential operation that must be performed by the auditory system. This auditory object recognition is a difficult task that requires selectivity to the group identifying acoustic features and invariance to renditions within each group. We find that small ensembles of auditory neurons in the forebrain of a social songbird can code the bird's entire vocal repertoire (∼10 call types). Ensemble neural discrimination is not, however, correlated with single unit selectivity, but instead with how well the joint single unit tunings to characteristic spectro-temporal modulations span the acoustic subspace optimized for the discrimination of call types. Thus, akin to face recognition in the visual system, call type recognition in the auditory system is based on a sparse code representing a small number of high-level features and not on highly selective grandmother neurons.

Is Urban Agriculture Sustaining the Urban Poor? A Study of Grandmother Headed Households (GHHs) in Bulawayo, Zimbabwe.

In this study of urban agriculture in Bulawayo, I examine the extent to which the activity sustains the poor and reduces social exclusion in grandmother-headed households. A qualitative case study design was employed to study the lives of 19 older women. Findings indicate that urban agriculture does not assist in reducing food insecurity and social exclusion among the research participants because of several factors. Challenges in acquiring farming land, medical conditions, and the strenuous and less integrated nature of the urban agriculture practice affect the extent to which urban agriculture secures families from hunger. Social assistance is needed for members of grandmother-headed households.

Maximal Dependence Capturing as a Principle of Sensory Processing.

Sensory inputs conveying information about the environment are often noisy and incomplete, yet the brain can achieve remarkable consistency in recognizing objects. Presumably, transforming the varying input patterns into invariant object representations is pivotal for this cognitive robustness. In the classic hierarchical representation framework, early stages of sensory processing utilize independent components of environmental stimuli to ensure efficient information transmission. Representations in subsequent stages are based on increasingly complex receptive fields along a hierarchical network. This framework accurately captures the input structures; however, it is challenging to achieve invariance in representing different appearances of objects. Here we assess theoretical and experimental inconsistencies of the current framework. In its place, we propose that individual neurons encode objects by following the principle of maximal dependence capturing (MDC), which compels each neuron to capture the structural components that contain maximal information about specific objects. We implement the proposition in a computational framework incorporating dimension expansion and sparse coding, which achieves consistent representations of object identities under occlusion, corruption, or high noise conditions. The framework neither requires learning the corrupted forms nor comprises deep network layers. Moreover, it explains various receptive field properties of neurons. Thus, MDC provides a unifying principle for sensory processing.

Paternal grandmother's smoking in pregnancy is associated with extreme aversion to bitter taste in their grandchildren.

Although there are many examples in the experimental literature of an environmental exposure in one generation impacting the phenotypes of subsequent generations, there are few studies that can assess whether such associations occur in humans. The Avon Longitudinal Study of Parents and Children (ALSPAC) has, however, been able to determine whether there are associations between grandparental exposures and their grandchildren's development. Several of our studies, including sensitivity to loud noise, have shown associations between a grandmother smoking in pregnancy and the phenotype of the grandchild. These results were mostly specific to the sex of the grandchild and to whether the prenatal (i.e. during pregnancy) smoking occurred in the maternal or paternal grandmother. Here, we have used ancestral data on prenatal smoking among the grandmothers of the ALSPAC index children to examine possible effects on the grandchild's ability to detect the bitter taste of PROP (6 n-propylthiouracil), distinguishing between the 10% deemed 'extreme tasters', and the rest of the population (total N = 4656 children). We showed that grandchildren whose paternal (but not maternal) grandmothers had smoked in pregnancy were more likely than those of non-smoking grandmothers to be extreme tasters [odds ratio (OR) 1.28; 95% confidence interval (CI) 1.03, 1.59] and that this was more likely in granddaughters (OR 1.42; 95% CI 1.03, 1.95) than grandsons (OR 1.18; 95% CI 0.88, 1.60). This pattern of association between paternal foetal exposure and the granddaughter's development has been found with several other outcomes, suggesting that investigations should be undertaken to investigate possible mechanisms.

What kind of network is the brain?

The different areas of the cerebral cortex are linked by a network of white matter, comprising the myelinated axons of pyramidal cells. Is this network a neural net, in the sense that representations of the world are embodied in the structure of the net, its pattern of nodes, and connections? Or is it a communications network, where the same physical substrate carries different information from moment to moment? This question is part of the larger question of whether the brain is better modeled by connectionism or by symbolic artificial intelligence (AI), but we review it in the specific context of the psychophysics of stimulus comparison and the format and protocol of information transmission over the long-range tracts of the brain.

The neural correlates of grandmaternal caregiving.

In many societies, grandmothers are important caregivers, and grandmaternal investment is often associated with improved grandchild well-being. Here, we present, to our knowledge, the first study to examine grandmaternal brain function. We recruited 50 grandmothers with at least one biological grandchild between 3 and 12 years old. Brain function was measured with functional magnetic resonance imaging as grandmothers viewed pictures of their grandchild, an unknown child, the same-sex parent of the grandchild, and an unknown adult. Grandmothers also completed questionnaires to measure their degree of involvement with and attachment to their grandchild. After controlling for age and familiarity of stimuli, viewing grandchild pictures activated areas involved with emotional empathy (insula and secondary somatosensory cortex) and movement (motor cortex and supplementary motor area). Grandmothers who more strongly activated areas involved with cognitive empathy (temporo-parietal junction and dorsomedial prefrontal cortex) when viewing pictures of the grandchild desired greater involvement in caring for the grandchild. Finally, compared with results from an earlier study of fathers, grandmothers more strongly activated regions involved with emotional empathy (dorsal anterior cingulate cortex, insula and secondary somatosensory cortex), and motivation (nucleus accumbens, ventral pallidum and caudate nucleus). All in all, our findings suggest that emotional empathy may be a key component of grandmaternal responses to their grandchildren.

Reevaluating the grandmother hypothesis.

Menopause is an evolutionary mystery: how could living longer with no capacity to reproduce possibly be advantageous? Several explanations have been offered for why female humans, unlike our closest primate relatives, have such an extensive post-reproductive lifespan. Proponents of the so-called "grandmother hypothesis" suggest that older women are able to increase their fitness by helping to care for their grandchildren as allomothers. This paper first distinguishes the grandmother hypothesis from several other hypotheses that attempt to explain menopause, and then develops a formal model by which these hypotheses can be compared and tested by empirical researchers. The model is then modified and used to respond to a common objection to the grandmother hypothesis: that human fathers, rather than grandmothers, are better suited to be allomothers due to their physical strength and a high incentive to invest in their own children. However, fathers-unlike maternal grandmothers-can never be sure that the children they are caring for are their own. Incorporating paternity uncertainty into the model demonstrates the conditions under which the grandmother hypothesis is more plausible than a hypothesis that focuses on the contributions of men.

Successful and Cost-Effective Facebook Recruitment: Is It Possible? Results From a Longitudinal Randomized Clinical Trial in Grandmother Caregivers.

Facebook is often cited in health-related research as a practical option to recruit participants into research studies, but issues with recruiting verifiable and qualified participants and unpredictable costs exist. The purpose of this paper is to describe a social network theory-guided, no-cost, Facebook recruitment strategy in comparison to a traditional recruitment campaign for a national online intervention study for grandmother caregivers (n = 348); 211 participants were recruited via Facebook, and 137 through traditional techniques. Participation rates did not vary by recruitment method. Facebook participants were slightly older, higher income, and more likely to be white and married, but did not differ in education levels. Our strategy quickly obtained an engaged and committed participant base. The application of social network theory to traditional recruitment strategies represents a novel way for researchers to recruit through Facebook and yield viable and engaged participants without investing in Facebook ads.

"We All Join Hands": Perceptions of the Kangaroo Method Among Female Relatives of Newborns in The Gambia.

Family support is essential for kangaroo mother care (KMC), but there is limited research regarding perceptions of female relatives, and none published from West African contexts. In-depth interviews were conducted from July to August 2017 with a purposive sample of 11 female relatives of preterm neonates admitted to The Gambia's referral hospital. Data were coded in NVivo 11, and thematic analysis was conducted applying an inductive framework. Female relatives were willing to support mothers by providing KMC and assisting with domestic chores and agricultural labor. Three themes were identified: (a) collective family responsibility for newborn care, with elder relatives being key decision makers, (b) balance between maintaining traditional practices and acceptance of KMC as a medical innovation, and (c) gendered expectations of women's responsibilities postnatally. Female relatives are influential stakeholders and could play important roles in KMC programs, encourage community ownership, and contribute to improved outcomes for vulnerable newborns.

Educational Attainment of Grandmothers and Preterm Birth in Grandchildren.

BACKGROUND: Maternal education has been shown repeatedly to be inversely associated with preterm birth. Both preterm birth and educational level of families are correlated across generations, but it is not clear if educational level of grandparents affects the risk of preterm delivery of their grandchildren, and, if so, if the association with grandmother's education is independent of mother's education. METHODS: We used New Jersey birth certificates to create a transgenerational dataset to examine the effect of grandmother's education on risk of PTB in White, Black and Hispanic grandchildren. We matched birth certificates of girls born in 1979-1983 to mothers listed on NJ birth certificates for the years 1999-2011. Thus, grandmothers were the women delivering in 1979-1983, and mothers were those born to the grandmothers who in turn delivered grandchildren in 1999-2011. We performed descriptive tabulations and multivariate logistic regression to develop risk estimates. RESULTS: Overall, maternal education was associated inversely with PTB in each of the demographic groups. There was a substantial inter-generational increase in education between grandmothers and mothers in each group, which was most striking in Hispanics After adjusting for maternal age and education, grandmother's education continued to be associated with preterm birth of her grandchildren. CONCLUSIONS: Grandmother's education was an additional, independent predictor of PTB in her grandchildren. This result supports the idea that mother's childhood and preconception socioeconomic environment, including the educational level of her childhood household affect her reproductive health.