Alloparental Support and Infant Psychomotor Developmental Delay.

Receiving social support from community and extended family has been typical for mothers with infants in human societies past and present. In non-industrialised contexts, infants of mothers with extended family support often have better health and higher survival through the vulnerable infant period, and hence shared infant care has a clear fitness benefit. However, there is scant evidence that these benefits continue in industrialised contexts. Better infant health and development with allocare support would indicate continued evolutionary selection for allocare. The research reported here used multiple logistic regression analysis to test whether a lack of family and other social support for mothers was associated with an increased risk of developmental delay in 9-month-old infants in the UK Millennium Cohort (analysis sample size, 15,696 infants). Extended family-based childcare during work hours and more maternal time spent with friends were the most influential kin and social support variables: infants of mothers with kin-based childcare versus all other childcare arrangements had a lower risk of developmental delay (OR = 0.61, 95% CIs: 0.46-0.82). Infants of mothers who spent no time with friends when compared with those who saw friends every day had double the odds of delay. Greater paternal involvement in infant care was associated with a lower odds of developmental delay. In conclusion, shared care of infants and social support for mothers may influence fitness-related traits in industrialised societies rather than being factors that influenced selection only in the past and in societies which retain close kin networks and a strong local community focus.

Influences of zero hour contracts and disability - Analysis of the 1970 British Cohort study.

Rationale: In recent decades, there has been a rise of the "gig-economy" where workers are given non-standard work agreements, and work is completed in an ad-hoc nature. It was believed people this would create greater access to employment for people with disability as there would no longer be a need to disclose disability and could 'pick and choose' work. Although, little research has been done on the health-outcomes of working in non-standard agreements compared to traditional employment, and in particular it's impact on disability. Objective: This study examines one particular non-standard workplace agreement, working under zero hour contracts as the main source of income as a predictor for disability at age 46 and how income levels effect this, while controlling for pre-existing illness at age 34. Method: This study used existing data made available in the 1970 British Cohort study. Age 46 and Age 34 sweeps were used, including predictors for disability such as zero hour work, sex, and income, and binary multiple logistic regression was used. Results: This study was able to demonstrate that there is an association between working under a zero hour contract as the main source of income and disability. Further, this study shows that this association is statistically significant at low incomes but not at high incomes. Conclusions: The relationship between zero hour work and disability presented in this study may suggest that zero hour work will produce a burden on healthcare systems and limit further economic outputs by limiting individual's capacity for work.

Test-enhanced learning improves learner attendance during a laparoscopic box trainer simulation program.

BACKGROUND: Laparoscopy is the gold standard approach for many surgical procedures, but it is a complex skill to learn. Laparoscopic simulation training may help, but it is unclear how to best engage trainees in these programs. Test-enhanced learning (TEL) uses regular, well-defined assessments of performance throughout the training phase of learning. AIM: The aim of this study was to assess the effects of TEL on a laparoscopic simulation program involving a cohort of medical student volunteers. MATERIALS AND METHODS: A prospective cohort study was performed with a convenience sample of 40 medical students. Students were recruited to participate in a ten-week laparoscopic simulation program. Twenty students participated in a laparoscopic surgical program with TEL ('TEL group'), and 20 students participated in a standard laparoscopic simulation program ('control group'). RESULTS: Attendance in the TEL group was significantly higher than in the standard group (71 vs 51.5%, P = 0.03). There was no difference between groups in mean time scores. Four themes were identified in qualitative data drawn from student surveys - personal traits and motivators, training context, clear goals and feedback enabling understanding of one's own performance. CONCLUSION: Testing laparoscopic skills throughout a learning program, in conjunction with individualised feedback and tracking of learning trajectory, increases trainee attendance. Laparoscopic simulation training programs are encouraged to reflect on the pedagogic framework in which their procedural skills training operates.

Mother-Infant Co-Sleeping and Maternally Reported Infant Breathing Distress in the UK Millennium Cohort.

Mother-infant co-sleeping or bed sharing is discouraged by health organisations due to evidence that it is associated with unexplained sudden infant death. On the other hand, there is evidence that it should theoretically be beneficial for infants. One line of this evidence concerns breathing regulation, which at night is influenced by the rocking movement of the mother's chest as she breathes. Here, the hypothesis that mother-infant co-sleeping will be associated with a lower probability of infant breathing distress is tested in the UK Millennium Cohort Study (n = 18,552 infants). Maternal, infant, family, and socio-economic covariates were included in logistic regression analysis, and in a machine learning algorithm (Random Forest) to make full use of the number of variables available in the birth cohort study data. Results from logistic regression analysis showed that co-sleeping was associated with a reduced risk of breathing difficulties (OR = 0.69, p = 0.027). The Random Forest algorithm placed high importance on socio-economic aspects of infant environment, and indicated that a number of maternal, child, and environmental variables predicted breathing distress. Co-sleeping by itself was not high in the Random Forest variable importance ranking. Together, the results suggest that co-sleeping may be associated with a modest reduction in risk of infant breathing difficulties.

Effects of Conception Using Assisted Reproductive Technologies on Infant Health and Development: An Evolutionary Perspective and Analysis Using UK Millennium Cohort Data.

Millions of infants around the world have been born as a result of assisted reproductive technologies (ART), and in the past three decades ART has become increasingly effective and technologically sophisticated. At the same time, advances have been made in understanding the evolutionary biology of mate choice and post-copulatory processes. These advances have relevance for ART as ART methods to a greater or lesser extent circumvent potentially important natural processes determining which fertilized embryo is successfully implanted. Here, using UK Millennium cohort data, the hypothesis that ART methods which circumvent both natural in vivo selection of ova and sperm (for example in vitro fertilization) lead to poorer child health and developmental outcomes than ART methods in which fertilization occurs naturally after fertility treatment using drugs or diathermy. The results showed that both groups of ART were associated with the number of infant health problems from birth through the first week of life when compared with naturally conceived infants. Methods with artificial fertilization were associated with two of the four most common health conditions: respiratory distress (OR 1.80; 95% CI 1.12-2.91) and infections (OR 1.77; 95% CI 1.96-2.06). ART methods with artificial fertilization were associated with delayed achievement of developmental milestones at nine months, and when contrasted with ART using fertility drugs or diathermy only, were significantly more likely to be associated with slower child development. This suggests that evolved processes that determine which egg and sperm lead to successful pregnancy may be important for offspring quality as indicated by infant development. Clinically, the results suggest that women should avoid ART with artificial gamete selection if they can conceive using other ART methods.

Unstable employment and health in middle age in the longitudinal 1970 British Birth Cohort Study.

BACKGROUND AND OBJECTIVES: Jobs for life have become increasingly rare in industrialized economies, and have been replaced by shorter-term employment contracts and freelancing. This labour market change is likely to be accompanied by physiological changes in individuals who have experienced little job stability. Evolved responses to increased environmental instability or stochasticity include increased fat deposition and fight-or-flight responses, such as glucose mobilization and increased blood pressure. These responses may have evolved by natural selection as beneficial to individuals in the short-term, but are damaging in the longer term. METHODOLOGY: This study tested whether job losses experienced between ages 30 and 42 are associated with increased body weight, hypertension and diabetes diagnosis in the 1970 British Birth Cohort, which consists of all registered births in a one-week period in April 1970. RESULTS: Each job loss experienced increased the odds of developing diabetes by 1.39 times (CI 1.08-1.80), and of hypertension by 1.28 times (CI 1.07-1.53). Another economic variable, higher personal debt, was associated with all three of these health outcomes: every £100 000 of debt roughly doubled the odds of gaining at least 5 kg between ages 30 and 42. CONCLUSIONS AND IMPLICATIONS: These associations between job loss and health-risk factors suggest that our changing economy results in increases in the prevalence of risk factors for cardiovascular disease. At a broader level, they are consistent with evolutionary understandings of environmental stochasticity, and are a reminder that economic policy is also health policy.

Male Facial Appearance and Offspring Mortality in Two Traditional Societies.

It has been hypothesised that facial traits such as masculinity and a healthy appearance may indicate heritable qualities in males (e.g. immunocompetence) and that, consequently, female preferences for such traits may function to increase offspring viability and health. However, the putative link between paternal facial features and offspring health has not previously been tested empirically in humans. Here we present data from two traditional societies with little or no access to modern medicine and family planning technologies. Data on offspring number and offspring survival were analysed for the Agta of the Philippines and the Maya of Belize, and archive facial photographs were assessed by observers for attractiveness and masculinity. While there was no association between attractiveness and offspring survival in either population, a quadratic relationship was observed between masculinity and offspring survival in both populations, such that intermediate levels of masculinity were associated with the lowest offspring mortality, with both high and low levels of masculinity being associated with increased mortality. Neither attractiveness nor masculinity were related to fertility (offspring number) in either population. We consider how these data may or may not reconcile with current theories of female preferences for masculinity in male faces and argue that further research and replication in other traditional societies should be a key priority for the field.

Reduced birth intervals following the birth of children with long-term illness: evidence supporting a conditional evolved response.

Human birth interval length is indicative of the level of parental investment that a child will receive: a short interval following birth means that parental resources must be split with a younger sibling during a period when the older sibling remains highly dependent on their parents. From a life-history theoretical perspective, it is likely that there are evolved mechanisms that serve to maximize fitness depending on context. One context that would be expected to result in short birth intervals, and lowered parental investment, is after a child with low expected fitness is born. Here, data drawn from a longitudinal British birth cohort study were used to test whether birth intervals were shorter following the birth of a child with a long-term health problem. Data on the timing of 4543 births were analysed using discrete-time event history analysis. The results were consistent with the hypothesis: birth intervals were shorter following the birth of a child diagnosed by a medical professional with a severe but non-fatal medical condition. Covariates in the analysis were also significantly associated with birth interval length: births of twins or multiple births, and relationship break-up were associated with significantly longer birth intervals.

Full medical program fees and medical student career intention.

OBJECTIVE: To explore the future career preferences of Commonwealth-supported place (CSP) and full-fee paying (FFP) medical students in Australia. DESIGN, SETTING AND PARTICIPANTS: Data from the Medical Schools Outcomes Database and Longitudinal Tracking (MSOD) Project exit questionnaire for CSP and FFP students who graduated between 2008 and 2011 were analysed using logistic regression. The influence of age, sex, marital status, rural background and fee-paying status on future career preference were explored. MAIN OUTCOME MEASURE: Future career preference (location and specialty) at graduation. RESULTS: Compared with CSP students, domestic FFP students were more likely to nominate as their first preference both urban locations (odds ratio [OR], 5.58; 95% CI, 2.04-15.26; P < 0.001) and higher-income specialties (OR, 1.37; 95% CI, 1.07-1.75; P < 0.05), and less likely to nominate as their first preference in-need specialties (OR, 0.72; 95% CI, 0.52-1.00; P < 0.05), specifically general practice (OR, 0.71; 95% CI, 0.52-0.99; P < 0.05). There was a significant domestic FFP student by marital status interaction effect, such that domestic FFP students who were married or partnered on exit from medical school were more likely to prefer a rural location (OR, 0.64; 95% CI, 0.44-0.95; P < 0.05). Also, students who were married or partnered were less likely to select a one of the higher-income specialties as their first preference (OR, 0.77; 95% CI, 0.64-0.92; P < 0.01). A rural background increased preferences for rural location (OR, 0.18; 95% CI, 0.15-0.22; P < 0.001) and in-need specialties (OR, 1.28; 95% CI, 1.04-1.57; P < 0.05), and being older on entry to medical school also increased preferences for rural location (OR, 0.96; 95% CI, 0.95-0.98; P < 0.001) and in-need specialties (OR, 1.03; 95% CI, 1.01-1.04; P < 0.01). International FFP students were more likely to prefer urban practice (OR, 1.79; 95% CI, 1.19-2.72; P < 0.01). CONCLUSION: Domestic FFP graduates are less likely to prefer careers in rural locations and in lower-paid and in-need specialties, particularly general practice. Current workforce implications might be minor, but if fees for CSP students increase or more FFP places become available, potential impacts on workforce distribution will need to be considered.

Life-history theory, chronic childhood illness and the timing of first reproduction in a British birth cohort.

Life-history theoretical models show that a typical evolutionarily optimal response of a juvenile organism to high mortality risk is to reach reproductive maturity earlier. Experimental studies in a range of species suggest the existence of adaptive flexibility in reproductive scheduling to maximize fitness just as life-history theory predicts. In humans, supportive evidence has come from studies comparing neighbourhoods with different mortality rates, historical and cross-cultural data. Here, the prediction is tested in a novel way in a large (n = 9099), longitudinal sample using data comparing age at first reproduction in individuals with and without life-expectancy-reducing chronic disease diagnosed during childhood. Diseases selected for inclusion as chronic illnesses were those unlikely to be significantly affected by shifting allocation of effort away from reproduction towards survival; those which have comparatively large effects on mortality and life expectancy; and those which are not profoundly disabling. The results confirmed the prediction that chronic disease would associate with early age at first reproduction: individuals growing up with a serious chronic disease were 1.6 times more likely to have had a first child by age 30. Analysis of control variables also confirmed past research findings on links between being raised father-absent and early pubertal development and reproduction.

Time allocation, religious observance, and illness in Mayan horticulturalists.

Analysis of individual differences in religious observance in a Belizean community showed that the most religious (pastors and church workers) reported more illnesses, and that there was no tendency for the religiously observant to restrict their interactions to family or extended family. Instead, the most religiously observant tended to have community roles that widened their social contact: religion did not aid isolation - thus violating a key assumption of the parasite-stress theory of sociality.

Grandparental investment and reproductive decisions in the longitudinal 1970 British cohort study.

There has been a recent increase in interest among evolutionary researchers in the hypothesis that humans evolved as cooperative breeders, using extended family support to help decrease offspring mortality and increase the number of children that can be successfully reared. In this study, data drawn from the 1970 longitudinal British cohort study were analysed to determine whether extended family support encourages fertility in contemporary Britain. The results showed that at age 30, reported frequency that participants saw their own parents (but not in-laws) and the closeness of the bond between the participant and their own parents were associated with an increased likelihood of having a child between ages 30 and 34. Financial help and reported grandparental childcare were not significantly positively associated with births from age 30 to 34. Men's income was positively associated with likelihood of birth, whereas women's income increased likelihood of birth only for working women with at least one child. While it was predicted that grandparental financial and childcare help would increase the likelihood of reproduction by lowering the cost to the parent of having a child, it appears that the mere physical presence of supportive parents rather than their financial or childcare help encouraged reproduction in the 1970 British birth cohort sample.

Evolution, obesity, and why children so often choose the unhealthy eating option.

In recent decades obesity has become an increasing concern for governments and health organisations around the world. Changes in diet in modern conditions have led to our food environment being labelled "toxic" and "obesogenic", and are portrayed in marked contrast to the types of food environment in which humans evolved and are adapted to biologically. In this article I question whether the modern food environment is genuinely so different from those that humans evolved in, and whether domesticated animals, like humans, tend to become obese in conditions where food is plentiful. I continue by offering a model of eating behaviour based on the marginal value theorem. The model implies that many parents and public policy unwittingly encourage unhealthy diets by controlling or over-regulating children's diet: although it may feel counterintuitive to respond to the risk of obesity by allowing individuals to make choices rather than restricting their choices, a more relaxed and less regulated approach to food intake should allow appropriate modulation of food intake in conditions where food is plentiful.

The influence of parent-infant cosleeping, nursing, and childcare on cortisol and SIgA immunity in a sample of British children.

Substantial variation in childcare arrangements exists both within and between populations. Research has suggested negative stress-related outcomes for children who regularly attend daycare facilities. In the present study, 122 cortisol and 94 secretory immunoglobulin A (SIgA) samples from 32 British children aged between 3 and 8 were analyzed using multilevel modeling to assess effects of daycare attendance and other childcare-related variables on children's stress and SIgA immune function. Parents' reports of children's aggression and family discord within 2 hr of saliva collection were associated with elevated cortisol levels in children. With these acute stressors statistically controlled, retrospective data on parent-child cosleeping showed that children who had coslept in their parent(s) room had lower cortisol levels, as did children who had attended less daycare in the first 4 years of life. The parenting-related variables did not predict SIgA immunity. The results are discussed in the context of theories of parenting strategies.