Social learning across the life cycle: cultural knowledge acquisition for honey collection among the Jenu Kuruba,India

Accounting for age-dependent patterns of knowledge transmission is critical for understanding cultural evolution in age-structured populations. Cultural evolution theory predicts which social learning biases we expect people to use, but much less often when—during a person's life cycle— different social learning biases will be used. By measuring knowledge and skill variation among age cohorts, it is possible to infer how people socially acquire different types of knowledge at different ages. We use this strategy among the Jenu Kuruba, a tribal community in South India. We document the accumulation of local knowledge required for collecting wild honey among 71 children and 125 adults from five communities. Combining quantitative measurements of knowledge with measures of four honey-collecting skills and self-reported data on learning age, we infer patterns of social learning across the lifecycle. We find that (1) most knowledge related to honey collecting is acquired by the early 20s, and later social learning mainly functions to update information; (2) the eldest cohort has the highest average explicit knowledge, although the most knowledgeable or skilled individuals do not always belong to the most elderly cohort; (3) length of learning can be affected by age-dependent trade-offs of costs and benefits to learners; and (4) children tend to learn from parents, but individuals use other demonstrators later in life. These results have implications for current models of cultural evolution.     

Parental teaching behavior in diverse cultural contexts

Humans, unlike any other species, have adapted to diverse environments across the globe due to cultural knowledge, skills, and practices. In early childhood, parent–child interactions play a pivotal role in cultural learning, but controversies about what constitutes teaching have stymied the systematic assessment of variation and similarities in parental teaching across cultures. We used a functional definition of teaching as behavior that evolved to facilitate learning in others and observed parents and their two-year-old child (N = 106) in a standardized setting (mealtime) in five diverse cultural contexts (rural: Brazil, Ecuador; urban: Argentina, Germany, Japan). Detailed coding of parental teaching (8520 teaching events in 1898 min of interactions) revealed that six teaching behaviors (prompts to do, prompts to stop, abstract communication of knowledge, demonstrations, providing choices, negative feedback) occurred frequently (> 5%) across contexts. At the same time, we found that the relative frequencies of these behaviors varied between contexts: Parents in rural contexts frequently used prompts towards their children. Parents in urban contexts often used abstract communication, demonstrations, and the provision of choices. We also identified nuanced differences between the urban samples regarding parental demonstrations (Japan) and the provision of choices (Germany). Our findings suggest that parents from all contexts mainly relied on a set of six teaching behaviors but that there was cross-cultural variation in how frequently behaviors occurred. Our study provides a cultural map of children's early learning experiences which lay the ontogenetic foundation for human cultural diversity.     

Savant skills in autism: psychometric approaches and parental reports

Most investigations of savant skills in autism are based on individual case reports. The present study investigated rates and types of savant skills in 137 individuals with autism (mean age 24 years). Intellectual ability ranged from severe intellectual impairment to superior functioning. Savant skills were judged from parental reports and specified as ‘an outstanding skill/knowledge clearly above participant''s general level of ability and above the population norm’. A comparable definition of exceptional cognitive skills was applied to Wechsler test scores—requiring a subtest score at least 1 standard deviation above general population norms and 2 standard deviations above the participant''s own mean subtest score. Thirty-nine participants (28.5%) met criteria for either a savant skill or an exceptional cognitive skill: 15 for an outstanding cognitive skill (most commonly block design); 16 for a savant skill based on parental report (mostly mathematical/calculating abilities); 8 met criteria for both a cognitive and parental rated savant skill. One-third of males showed some form of outstanding ability compared with 19 per cent of females. No individual with a non-verbal IQ below 50 met criteria for a savant skill and, contrary to some earlier hypotheses, there was no indication that individuals with higher rates of stereotyped behaviours/interests were more likely to demonstrate savant skills.     

Development of Social Variation in Reproductive Schedules: A Study from an English Urban Area

Background

There is striking social variation in the timing of the onset of childbearing in contemporary England, with the mean age at first motherhood about 8 years earlier in the most deprived compared to the least deprived neighbourhoods. However, relatively little is known about how these social differences in reproductive schedule develop in childhood.

Methodology/Principal Findings

We studied the development of differences in reproductive schedules, using a cross-sectional survey over 1000 school students aged 9–15 in the metropolitan borough of North Tyneside. Students from more deprived neighbourhoods had earlier ideal ages for parenthood than those from more affluent ones, and these differences were fully apparent by age 11. We found evidence consistent with three mechanisms playing a role in maintaining the socioeconomic gradient. These were: vertical intergenerational transmission (students whose own parents were younger at their birth wanted children younger); oblique intergenerational transmission (students in neighbourhoods where parents were younger in general wanted children earlier); and low parental investment (students who did not feel emotionally supported by their own parents wanted children at a younger age).

Conclusions/Significance

Our results shed some light on the proximate factors which may be involved in maintaining early childbearing in disadvantaged communities. They help understand why educational initiatives aimed at adolescents tend to have no effect, whereas improving the well-being of poor families with young children may do so. Our results also suggest that there will be considerable intergenerational inertia in the response of reproductive schedules to changing socioecological conditions.     

Associations between multiple measures of parental feeding and children's adiposity in United Kingdom preschoolers

Objective: Research into the association between parental control over feeding and children's adiposity has produced inconclusive results. Some studies have found parental control to be associated with unhealthy food choices and disordered intake regulation, whereas others have found favorable or null associations between control and adiposity. This study hypothesized that variability in measures of parental feeding could contribute to these discrepancies. Scales from a range of existing parental feeding questionnaires were used together, in the same large sample of children, to examine associations with adiposity. Research Methods and Procedures: Associations between scores on scales from three published parental feeding questionnaires [Child Feeding Questionnaire (CFQ); Preschooler Feeding Questionnaire (PFQ); and Parental Feeding Style Questionnaire (PFSQ)] and children's BMI z‐scores, calculated from measured heights and weights, were examined in a socioeconomically diverse sample of 439 parents and their 3‐ to 5‐year‐old children. Results: Higher scores on CFQ Pressure to Eat and PFQ Pushing the Child to Eat More were significantly associated with lower BMI z‐score, while PFSQ Prompting to Eat, CFQ Restriction, PFSQ Instrumental Feeding, and PFSQ Emotional Feeding were unassociated with BMI z‐score. Discussion: These results suggest that parents of leaner children are more likely to encourage their children to eat. Other feeding strategies seemed to have negligible relationships with children's BMI z‐scores at this stage. Longitudinal and genetically informed designs are needed to clarify the causal pathways between parental feeding and children's adiposity.     

Dreaming in Spain: parental determinants of immigrant children's ambition

We examine determinants of educational and occupational aspirations and expectations among children of immigrants in Spain on the basis of a unique data set that includes statistically representative data for foreign-origin secondary students in Madrid and Barcelona plus a sample of one-fourth of their parents. Independently collected data for both generations allow us to establish effects of parental characteristics on children's orientations without the confounding potential inherent in children's reports about parents. We analyse first determinants of parental ambition and, through a series of stepwise regressions, the effects of these goals and other parental and family characteristics on children's aspirations and expectations. A structural equations model synthesizes the results of the analysis. The model confirms predictions from the research literature, especially those based on the Wisconsin status attainment model, but rejects others, including the predicted significance of private versus public school attendance. Parental ambition, knowledge of Spanish by parents and children, gender and children's age are major determinants of youths' educational and occupational goals. These results have direct implications for policy; these are discussed in the conclusion.     

Exploring the Relation of Harsh Parental Discipline with Child Emotional and Behavioral Problems by Using Multiple Informants. The Generation R Study

Parental harsh disciplining, like corporal punishment, has consistently been associated with adverse mental health outcomes in children. It remains a challenge to accurately assess the consequences of harsh discipline, as researchers and clinicians generally rely on parent report of young children''s problem behaviors. If parents rate their parenting styles and their child''s behavior this may bias results. The use of child self-report on problem behaviors is not common but may provide extra information about the relation of harsh parental discipline and problem behavior. We examined the independent contribution of young children''s self-report above parental report of emotional and behavioral problems in a study of maternal and paternal harsh discipline in a birth cohort. Maternal and paternal harsh discipline predicted both parent reported behavioral and parent reported emotional problems, but only child reported behavioral problems. Associations were not explained by pre-existing behavioral problems at age 3. Importantly, the association with child reported outcomes was independent from parent reported problem behavior. These results suggest that young children''s self-reports of behavioral problems provide unique information on the effects of harsh parental discipline. Inclusion of child self-reports can therefore help estimate the effects of harsh parental discipline more accurately.     

A synthetic biosocial model of fertility transition: Testing the relative contribution of embodied capital theory,changing cultural norms,and women's labor force participation

This article presents a biosocial model of fertility decline, which integrates ecological‐economic and informational‐cultural hypotheses of fertility transition in a unified theoretical framework. The model is then applied to empirical data collected among 500 women from San Borja, Bolivia, a population undergoing fertility transition. Using a combination of event history analysis, multiple regression, and structural equation modeling, we examine the pathways by which education responds to birth cohort, parental education and network ties, and how age at first birth and total fertility, in turn, respond to birth cohort, social network ties, education, expectations about parental investment, work, and contraceptive use. We find that in addition to secular trends in education, respondent's education is associated with the education of parents, the investment she received from them, and the education of older siblings. Total fertility has dropped over time, partly in response to increased education; moreover, the behavior of other women in a woman's social network predicts both initiation of reproduction and total fertility, while expected parental investment in offspring negatively predicts total fertility. Involvement in paid work that is incompatible with childcare is associated with a later age of first reproduction, but not subsequent fertility. Contraceptive use partially mediates the effect of education and birth cohort on total fertility, but is not a mediator of the effect of social network or expected parental investment on total fertility. Overall, the empirical results provide support for a biosocial model of fertility decline, particularly the embodied capital and cultural pathways. Am J Phys Anthropol 154:322–333, 2014. © 2014 Wiley Periodicals, Inc.     

Classroom Race/Ethnic Composition,Family-School Connections,and the Transition to School

Using data from the Early Childhood Longitudinal Study–Kindergarten Cohort (N = 13,970), we examined whether two aspects of school-family connections, parental involvement and communication quality, accounted for the association between classroom composition and children's academic and socioemotional functioning following the transition to elementary school. For students with more same-race/ethnic representation in their classrooms, greater classroom race/ethnic diversity promoted more parental involvement, which in turn promoted children's interpersonal skills and reading achievement. Classroom diversity made little difference to parental involvement when students had fewer same-race/ethnic peers in the classroom. Teacher–parent communication quality did not emerge as an explanatory mechanism, and findings did not vary by the race/ethnic match between students and their teachers.     

Development of Overweight in Children in Relation to Parental Weight and Socioeconomic Status

The purpose of the study was to test the hypothesis that socioeconomic status (SES) moderates the association between parental weight and changes in BMI from childhood to early adolescence. Participants included 428 twin children from 100 families with obese parents (“obese families”) and 114 sociodemographically matched families with normal‐weight parents (“lean families”) who were assessed in their homes (age = 4.4). Follow‐up study was conducted 7 years later (age = 11.2) on 346 children (81%). Complete data were available for 333 children. Family SES was indexed with maternal education. Children's weights and heights were measured to calculate BMI s.d. scores based on 1990 British norms. Overweight was defined as >91st BMI centile. In children with obese parents, BMI s.d. scores increased from 0.51 at age 4 to 1.06 at age 11. In children with lean parents, BMI s.d. scores decreased from 0.11 to 0.05. Prevalence of overweight remained stable from age 4 to 11 in children with lean parents (8% to 9%), but it more than doubled in children with obese parents (17% to 45%). There was a significant interaction between parental weight and family SES (P < 0.01), so that in children with lean parents there was no SES difference in the BMI status from age 4 to 11; however, in children with obese parents, the increase in adiposity was significantly greater in lower SES families. These results suggest that parental leanness confers significant protection against development of overweight in children regardless of family SES, while parental obesity is an adverse prognostic sign, especially in lower SES families.     

Cultural Identity and Internationally Adopted Children: Qualitative Approach to Parental Representations

Approximately 30 000 children are adopted across national borders each year. A review of the literature on the cultural belonging of these internationally adopted children shows substantial differences between the literature from English-speaking countries and that from France and Europe in general. The objective of this study is to start from the discourse of French adoptive parents to explore their representations of their child''s cultural belonging and their positions (their thoughts and representations) concerning connections with the child''s country of birth and its culture. The study includes 51 French parents who adopted one or more children internationally. Each parent participated in a semi-structured interview, focused on the adoption procedure and their current associations with the child''s birth country. The interviews were analyzed according to a qualitative phenomenological method, Interpretative Phenomenological Analysis. The principal themes that emerged from our analysis of the interviews made it possible to classify the parents into three different groups. The first group maintained no association with the child''s country of birth and refused any multiplicity of cultural identities. The second group actively maintained regular associations with the child''s country of birth and culture and affirmed that their family was multicultural. Finally, the third group adapted their associations with the child''s birth country and its culture according to the child''s questions and interests. Exploring parental representations of the adopted child enables professionals involved in adoption to provide better support to these families and to do preventive work at the level of family interactions.     

Transgenerational interactions involving parental age and immune status affect female reproductive success in Drosophila melanogaster

It is well established that the parental phenotype can influence offspring phenotypic expression, independent of the effects of the offspring''s own genotype. Nonetheless, the evolutionary implications of such parental effects remain unclear, partly because previous studies have generally overlooked the potential for interactions between parental sources of non-genetic variance to influence patterns of offspring phenotypic expression. We tested for such interactions, subjecting male and female Drosophila melanogaster of two different age classes to an immune activation challenge or a control treatment. Flies were then crossed in all age and immune status combinations, and the reproductive success of their immune- and control-treated daughters measured. We found that daughters produced by two younger parents exhibited reduced reproductive success relative to those of other parental age combinations. Furthermore, immune-challenged daughters exhibited higher reproductive success when produced by immune-challenged relative to control-treated mothers, a pattern consistent with transgenerational immune priming. Finally, a complex interplay between paternal age and parental immune statuses influenced daughter''s reproductive success. These findings demonstrate the dynamic nature of age- and immune-mediated parental effects, traceable to both parents, and regulated by interactions between parents and between parents and offspring.     

Control of parental investment changes plastically over time with residual reproductive value

Evolutionary conflict between parents and offspring over parental resource investment is a significant selective force on the traits of both parents and offspring. Empirical studies have shown that for some species, the amount of parental investment is controlled by the parents, whereas in other species, it is controlled by the offspring. The main difference between these two strategies is the residual reproductive value of the parents or opportunities for future reproduction. Therefore, this could explain the patterns of control of parental investment at the species level. However, the residual reproductive value of the parents will change during their lifetime; therefore, parental influence on the amount of investment can be expected to change plastically. Here, we investigated control of parental investment when parents were young and had a high residual reproductive value, compared to when they were old and had a low residual reproductive value using a cross‐fostering experiment in the burying beetle Nicrophorus quadripunctatus. We found that parents exert greater control over parental investment when they are young, but parental control is weakened as the parents age. Our results demonstrate that control of parental investment is not fixed, but changes plastically during the parent's lifetime.     

The Educational Benefits of a Ten-Week Home-Based Wild Bird Feeding Program for Children

ABSTRACT

This study evaluated a ten-week educational home-based program for feeding wild birds, intended to increase elementary school age children's knowledge about birds, especially those wild birds commonly encountered at outdoor home feeders. We measured changes from pre- to post-program in 65 seven- to 12-year old children's knowledge about wild birds, as well as in environmental attitudes. The goal was not only to increase bird knowledge in the target child but also to involve other family members in home-based nature education activities. After the program, seven- to nine-year old boys and girls showed significant gains in bird knowledge, but older children (10–12 years) did not significantly improve. Children's increased knowledge was positively associated with parental education. There was no systematic change in environmental attitudes. Parents identified family involvement as a particularly beneficial aspect of the program, and 90% of contacted families were still feeding birds one year after program termination.     

Social Networks and Knowledge Transmission Strategies among Baka Children,Southeastern Cameroon

The dynamics of knowledge transmission and acquisition, or how different aspects of culture are passed from one individual to another and how they are acquired and embodied by individuals, are central to understanding cultural evolution. In small-scale societies, cultural knowledge is largely acquired early in life through observation, imitation, and other forms of social learning embedded in daily experiences. However, little is known about the pathways through which such knowledge is transmitted, especially during middle childhood and adolescence. This study presents new empirical data on cultural knowledge transmission during childhood. Data were collected among the Baka, a forager-farmer society in southeastern Cameroon. We conducted structured interviews with children between 5 and 16 years of age (n?=?58 children; 177 interviews, with children being interviewed 1–6 times) about group composition during subsistence activities. Children’s groups were generally diverse, although children tended to perform subsistence activities primarily without adults and with same-sex companions. Group composition varied from one subsistence activity to another, which suggests that the flow of knowledge might also vary according to the activity performed. Analysis of the social composition of children’s subsistence groups shows that vertical and oblique transmission of subsistence-related knowledge might not be predominant during middle childhood and adolescence. Rather, horizontal transmission appears to be the most common knowledge transmission strategy used by Baka children during middle childhood and adolescence, highlighting the importance of other children in the transmission of knowledge.     

Offspring quality and tick infestation load in brood rearing great tits Parus major

Although the impact of nest-dwelling ectoparasites on nestlings in altricial birds is relatively well documented, little information is available on the fitness consequences of bird–ectoparasite systems with limited ectoparasite transmission between parents and their offspring. In this particular context we tested the hypothesis that parental infestation by a haematophageous field ectoparasite, the sheep tick Ixodes ricinus , in a hole-breeding passerine bird, the great tit Parus major , ultimately leads to the reduction of nestling quality. Observational data of a long-term study show that 15 days after hatching, nestlings' body condition (body mass corrected for body size) was negatively associated with the tick load of the mother, while no association was found with tick load of the father. A field experiment was conducted to test if adult infestation by ticks leads to a reduction in offspring quality. The field experiment consisted of a two by two factorial design: neither, one or both parents were infested with a high tick load (12 nymphs) when nestlings were eight days old. Four days after manipulation of the parents, the effect of the treatment on nestlings' health was assessed by measuring haematological and biochemical parameters. Body condition of nestlings was monitored from three days after hatching, until seven days after tick manipulation of the parents. Although parental tick manipulation resulted in successful tick feeding, nestlings' health parameters were not affected. We therefore suggest that the negative association between nestling condition and parental tick load does not reflect a causal effect of parasites, but either reflects a common environmental factor affecting parental infestation levels and offspring condition, or reflects parental quality. We propose different explanations why this association is expressed in female parents only.     

Parental attachment and children's memory for attachment-relevant stories

Despite evidence that parents’ attachment is associated with children's memory, less is known about the mechanisms underlying this association or the contexts in which the association is most meaningful. The present study examined whether parents’ attachment predicted children's memory for stories regarding attachment-related topics, whether the cohesiveness of children's stories mediated the association between attachment and memory, and whether the association varied by interview support at retrieval. Five- to six-year-olds completed attachment-relevant stories while parents provided information about their romantic attachment. Children's stories were coded for cohesiveness. A week later, children's memory for their stories was tested by either a supportive or nonsupportive interviewer. When the interview was nonsupportive, greater parental avoidance was associated with poorer memory, whereas when the interview was supportive, greater parental avoidance was associated with fewer errors. Findings provide insight into the context under which parents’ attachment is most influential in shaping children's memory.     

Foraging behaviour alters with social environment in a juvenile songbird

Early independence from parents is a critical period where social information acquired vertically may become outdated, or conflict with new information. However, across natural populations, it is unclear if newly independent young persist in using information from parents, or if group-level effects of conformity override previous behaviours. Here, we test if wild juvenile hihi (Notiomystis cincta, a New Zealand passerine) retain a foraging behaviour from parents, or if they change in response to the behaviour of peers. We provided feeding stations to parents during chick-rearing to seed alternative access routes, and then tracked their offspring''s behaviour. Once independent, juveniles formed mixed-treatment social groups, where they did not retain preferences from their time with parents. Instead, juvenile groups converged over time to use one access route­ per group, and juveniles that moved between groups switched to copy the locally favoured option. Juvenile hihi did not copy specific individuals, even if they were more familiar with the preceding bird. Our study shows that early social experiences with parents affect initial foraging decisions, but social environments encountered later on can update transmission of arbitrary behaviours. This suggests that conformity may be widespread in animal groups, with potential cultural, ecological and evolutionary consequences.     

Parental age and lifespan influence offspring recruitment: a long-term study in a seabird

Recent studies of wild populations provide compelling evidence that survival and reproduction decrease with age because of senescence, a decline in functional capacities at old ages. However, in the wild, little is known about effects of parental senescence on offspring quality. We used data from a 21-year study to examine the role of parental age on offspring probability of recruitment in a long-lived bird, the blue-footed booby (Sula nebouxii). Offspring probability of recruiting into the breeding population varied over the life of parents and effects age were similar in mothers and fathers. Offspring recruitment was high when parents were roughly 6-12 years old and low before and after then. Effects of parental age on offspring recruitment varied with lifespan (parental age at last reproduction) and previous breeding experience. Offspring recruitment from young and old parents with long reproductive lifespans was greater than that of offspring from parents with short lifespans at young and old ages. For parents with little previous breeding experience recruitment of offspring decreased with their hatch date, but experienced parents were no similarly affected. We found evidence of terminal effects on offspring recruitment in young parents but not in older parents, suggesting that senescence is more likely a gradual process of deterioration than a process of terminal illness. Failure to recruit probably reflects mortality during the first years after independence but also during the fledgling transition to full independence. Our results show effects of parental age and quality on offspring viability in a long-lived wild vertebrate and support the idea that wild populations are composed of individuals of different quality, and that this individual heterogeneity can influence the dynamics of age-structured populations.