Parental Investment Research Articles

Parental Investment, Status, and Child Gender: Some Evidence for the Trivers–Willard Hypothesis from a Survey Experiment

This study critically evaluates and empirically tests the Trivers–Willard (TW) hypothesis, which proposes a relationship between parental socioeconomic status and sex: Parents with higher status are expected to be more likely to have male offspring and to preferentially invest in male offspring, whereas parents with lower status are expected to be more likely to have female offspring and to preferentially invest in daughters. Although the TW hypothesis has been explored in terms of offspring sex ratio and parental investment, findings in modern developed societies generally show null results, with notable exceptions in the domain of parental investment in their children’s education. Previous studies have often not explicitly addressed the potential underlying mechanisms of the TW effect. This includes the authors of the original hypothesis (Trivers and Willard 1973), who discussed some potential mechanisms but ultimately left the question of mechanisms unanswered. Building on Matthews’s (2011) proposition to explore psychological underpinnings, this paper posits that the TW effect, if present, may be rooted in general parental preferences. To investigate this, a factorial survey experiment was designed to measure respondents’ preferences in parental investment while minimizing social desirability bias. The study specifically examines the extent to which respondents’ assessments of favorability and fairness in various parental investment scenarios depend on child characteristics believed to influence differential parental behavior. The findings reveal patterns that are somewhat in line with the TW hypothesis but are minor and lack statistical significance. The article concludes by proposing three future research directions aimed at further unraveling the intricacies of the TW effect.

Analysis of Parental Investment Mode of Multi-child Families in China——The Influence of Sex and Age on Parents' Investment Choice

With the progress of society and economic development, the quality and quantity of parental investment have an important impact on the future achievements of children. This study will use questionnaires and interviews to explore the specific effects of child gender and age on parental investment choice in multi-child families, and analyze the history of parental investment, problems, challenges, and impacts in multi-child families. The research shows that the parental investment mode of parents in their children tends to be diversified and personalized; the possible problems include economic pressure, educational pressure, family relationship pressure and emotional investment imbalance; the gender and difference may challenge the shaping of mate selection and parenting concept; and the influence aspects include economic pressure, educational resources and change of family relationship.

Impact of Parental Time Investment on Child Development among Dual Income Family

This cross-sectional study investigates how early childhood development is impacted by parental time commitment in the Horizon Hill dual-income family community. This study employs quantitative method approach to examine how changes in parental engagement dynamics affect children's behavior, mental health, and cognitive functioning both before and after the intervention. The results demonstrate that families have a great involvement rate, with 10 out of 11 demonstrating a strong dedication to enhancing their children's developmental experiences through the program's seamless integration into their daily routines. The results also show that advances in children's cognitive, social, emotional, and behavioral dimensions positively correspond with higher parental investment. These findings highlight how important parental participation is in helping Horizon Hill neighborhood children have great early experiences. This study has ramifications that go beyond improving child well-being and encouraging good parenting techniques through community-based interventions. By comprehending how parental time investment affects child development, policymakers and practitioners can create focused initiatives that enable parents to create caring environments that support their kids' development and success. This study adds to our understanding of the dynamics of parent-child relationships and emphasizes how important it is to spend quality time raising children to promote positive developmental outcomes.

Variation in parental investment preferences for nestlings of the Gray‐backed Shrike (Lanius tephronotus) in alpine environments

AbstractIn the northeastern edge of the Qinghai‐Tibet Plateau, the Gray‐backed Shrike, a shrubland bird species of the plateau, confronts harsh living conditions. The impact of such an environment on their reproductive strategies has long intrigued us. This study reveals significant environmental effects on the investment of the Gray‐backed Shrike during their nestling‐rearing and egg‐laying stages. (1) Based on measurements of 215 shrike eggs from 2017 to 2021, we found that under the cold alpine climate, Gray‐backed Shrikes opt for a strategy of larger clutches and bigger eggs as average rainfall decreases. Concurrently, parents display a decreasing hatching order strategy, resulting in significant weight differences among newly hatched nestlings. (2) Marginal and core offspring exhibited no significant differences in fledging conditions. Core offspring generally have a slightly larger physique than marginal ones. However, marginal offspring exhibit the highest growth rate, with similar survival rates across different offspring categories. Parental rearing adopts a nest survival strategy. (3) The food provisioning rate by parents correlates strongly with the number of nestlings, the age of the nestling, and the nest's sex ratio. Differences exist between female and male provisioning rates based on begging intensity and average temperature; higher average temperatures lead to more food, with males providing more food. (4) Factors like nest sex ratio, offspring category, nestling age, and nestling sex influence the feeding preferences of parents. When overall nestling ratios skew towards either male or female, parental feeding preferences align with the actual nest sex ratio. Male and female parental feeding preferences differ based on average temperature and nestling sex. Males consistently exhibit a stronger preference for feeding male nestlings, regardless of the nest's sex ratio. In contrast, females don't show a clear preference, leading to differences in survival rates for different nestling sex under male feeding preferences.

Food supplementing peregrine falcon (Falco peregrinus tundrius) nests increase reproductive success with no change in mean parental provisioning rate.

Parents are expected to exhibit intermediate levels of investment in parental care that reflect the trade-off between current versus future reproduction. Providing parents with supplemental food may allow for increased care to the current brood (additive model), re-allocation of parental effort to other behaviours such as self-maintenance (substitution model), or may provide parents with a buffer against provisioning shortfalls (insurance model). We investigated the impact of parental food supplementation on provisioning behaviour and breeding success in Arctic-breeding peregrine falcons (Falco peregrinus tundrius) over five successive breeding seasons (2013-2017). We found that supplemental feeding had no impact on mean provisioning rates, yet resulted in increased nestling survival probability, increased nestling body mass and decreased variance in nestling body mass and provisioning rates. These results are consistent with parents adopting a hybrid of the additive and substitution models. We suggest that food supplementation enables increased investment in other forms of parental care (e.g. nest defence, brooding) without altering mean provisioning rates. The lack of observed effects on mean provisioning rates, coupled with increased survival and body mass of offspring, suggests a potential reallocation of parental effort. The findings contribute to understanding the responses of peregrine falcons to food supplementation, highlighting the need for future studies to explore broader environmental contexts and potential long-term effects on parental survival and future reproduction.

Maternal risk-management elucidates the evolution of reproductive adaptations in sharks by means of natural selection

Maternal investment theory is the study of how breeding females allocate resources between offspring size and brood size to achieve reproductive success. In classical trade-off models, r/K-selection and bet-hedging selection, the primary predictors of maternal investments in offspring are population density and resource stability. In crowded, stable environments, K-selected females invest in large offspring at an equivalent cost in brood size. In uncrowded, unstable environments, r-selected females invest in large broods at an equivalent cost in offspring size. In unpredictable resource environments, bet-hedging females invest moderately in brood size and offspring size. The maternal risk-management model represents a profound departure from classical trade-off models. Maternal investments in offspring size, brood size, and brood number are shaped independently by autonomous risk factors: the duration of gaps in resources during seasonal cycles, rates of predation, and unpredictable catastrophic events. To date, no single model has risen to a position of preeminence. Here in sharks, we show that maternal investments within and across species do not agree with the predictions of trade-off models and instead agree with the predictions of the maternal risk-management model. Within and across shark species, offspring size and brood size were independent maternal investment strategies. The risk of starvation favored investments in larger offspring. The risk of predation favored investments in larger broods. If empirical studies continue to confirm its predictions, maternal-risk management may yet emerge as a unifying model of diverse reproductive adaptations by means of natural selection.

Brooding duration does not depend on cat predation risk but is related to weather and phenology in the wandering albatross (Diomedea exulans).

Parental investment increases offspring fitness at the expense of the parent's ability to invest in other offspring. In many animal species, parents guard their offspring after birth. The parental decision over the duration of this period is expected to be triggered by the associated fitness costs and benefits for both offspring and parents. Here, we evaluated the relevance of several intrinsic and environmental variables in determining brooding period duration in the wandering albatross (Diomedea exulans) and questioned whether brooding duration was related to chick subsequent survival and biometry prior to fledging. We used a semi-experimental design to increase the variance in cat abundance, a recent predator of albatross chicks, and predicted that an increased predation risk at the nest scale would trigger longer chick brooding and thus, protection. In addition, we questioned the influence of weather conditions, hatching date, and characteristics of chicks (sex and biometry) and parents (sex and age) on brooding duration. We report no effect of predation risk or parental characteristics on brooding duration. However, the probability for a parent to end brooding decreased with forthcoming unfavorable weather. Our data also revealed reduced brooding duration for late-hatched chicks and a positive association between brooding duration and chick structural size, and between the frequency of shifts between parents and chick structural size. Finally, brooding duration was not associated with chick survival or with chick biometry prior to fledging. We discuss these results in light of pre-existing hypotheses on fitness costs and benefits associated with brooding duration for chicks and parents.

Male condition and seminal fluid affect female host-marking behavior in the Mexican fruit fly

Mating and the transfer of seminal fluid components including male accessory glands (MAGs) proteins can affect oviposition behavior in insects. After oviposition, some species of fruit flies deposit a host-marking pheromone (HMP) on the fruit that discourages oviposition by other females of the same or different species or genus and reduces competition between larvae. However, we know very little about how mating, receiving seminal fluid, or male condition can affect female host marking behavior. Here, we tested how the physiological state of females (mated or unmated), the receipt of seminal fluid, and the condition of the male (wild or sterile) affect oviposition and host-marking behavior (HMB) in Anastrepha ludens (Diptera: Tephritidae). We also determined the efficiency of the host-marking pheromone from mated or unmated females in deterring oviposition. In a further examination of how seminal fluid may be affecting HMB we assessed if there were differences in the size of wild or sterile MAGs and the protein quantity transferred during mating. Our results indicate that receiving seminal fluid increased egg laying and increased time invested in host-marking (HM). Unmated females laid fewer eggs than mated females but invested the same amount of time in depositing host-marking pheromone, which had similar effectiveness in deterring oviposition as that of mated females. Females that mated with sterile males laid the same number of eggs as females that mated with wild males but spent less time depositing host-marking pheromone, which suggests that females detect the condition of the male and invest less in marking hosts. Finally, sterile males had larger accessory glands and transferred more MAGs proteins during mating compared to wild males. Seminal proteins could be manipulating HM behavior and female investment into their current reproductive effort. We are only beginning to understand how male condition and seminal fluid can affect female physiology and maternal investment in HMP.

Religious Involvement Is Associated With Higher Fertility and Lower Maternal Investment, but More Alloparental Support Among Gambian Mothers.

Human childrearing is cooperative, with women often able to achieve relatively high fertility through help from many individuals. Previous work has documented tremendous socioecological variation in who supports women in childrearing, but less is known about the intracultural correlates of variation in allomaternal support. In the highly religious, high-fertility setting of The Gambia, we studied whether religious mothers have more children and receive more support with their children. We randomly sampled 395 mothers and 745 focal children enrolled in the Kiang West (The Gambia) Longitudinal Population Study cohort. Structured interviews asked mothers who and how often people invest in their children, and about their religious practices. Data were collected at participants' homes on electronic tablet-based long-form surveys and analyzed using the Bayesian hierarchical models. Religiosity was weakly associated with women's higher age-adjusted fertility. Maternal religiosity was negatively related to maternal investment in focal children, but positively associated with total allomaternal support. Specifically, a woman's religiosity was positively associated with allomaternal support from matrilineal kin, other offspring, and affinal kin, but unrelated to paternal, patrilineal, and non-kin investment. These results suggest that higher fertility among religious mothers may be supported by high levels of investment from biological and affinal kin. Matrilineal kin, other siblings, and affinal kin seem to be the most responsive to a woman's religiosity. Our findings cast doubt on interpretations of women's religious behaviorsas signals of fidelity, and instead suggest theymay be part of strategies to enable collective allomaternal resources and higher relative fertility.

Parent psychological distress and beliefs about nurturing care: Associations with parent investments and early child development in Ethiopia.

Parental engagement in stimulating activities and support in both formal and informal learning environments are important for early childhood development. However, little is known about how parental mental health and beliefs about early childhood development shape such investments. We draw on a sample of young children and their primary caregiver from Addis Ababa, Ethiopia (N = 3,000; Mage = 34.1 months; 48.5% girls) and examine how parental distress and beliefs predict investments in learning at home and how these, in turn, predict children's development across multiple domains. We examine these associations separately for infants/toddlers (0-35 months) and preschool-aged children (36-72 months), for whom enrollment in preprimary school is also included as an additional form of parent investment. Results showed different patterns of associations between the two age groups. Specifically, for infants and toddlers, parental distress and beliefs did not predict parent investments or child outcomes, but both access to learning materials and cognitive stimulation at home positively predicted child development in every domain. For preschool-aged children, parental beliefs positively predicted hours in preschool, and parental distress negatively predicted the availability of learning materials and cognitive stimulation at home; these three forms of parent investments each positively predicted children's outcomes across all developmental domains. Collectively, these findings deepen our understanding of parent factors that shape children's formal and informal learning experiences and point to several important areas for future research to more fully understand early childhood development in low-resource contexts. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Evolutionary transitions of decapod crustaceans to non-marine, polar, and deep-sea environments: developmental, physiological and biochemical adaptations

Abstract In this brief, non-exhaustive essay, we review major adaptive changes in reproductive and developmental traits of decapod crustaceans, which have passed through evolutionary transitions from ancestral life in coastal marine environments to brackish, limnic, polar, or deep-sea habitats. Two major approaches can be recognised in studies of life-history evolution, focussing on: (1) developmental changes in adaptive physiological or biochemical traits of successive ontogenetic stages, comparing, for instance, osmoregulatory capabilities in larvae, juveniles, and adults (“ontogeny of adaptations” perspective); (2) adaptive changes in the modes of reproduction and development, e.g., enhanced maternal energy investment in egg production, abbreviated, non-feeding larval development (“adaptations in ontogeny”). Using both scientific approaches, Christoph D. Schubart has significantly contributed to our understanding of evolutionary transitions in crustaceans. In our essay, we pay particular attention to the significance of nutritional selection factors in relation to presumably adaptive developmental, physiological, and biochemical traits in different life-history stages. In this context, we highlight the key roles of lipids and carotenoid pigments, in particular of essential polyunsaturated fatty acids (PUFAs) and astaxanthin. While PUFAs and other lipid compounds have received wide scientific attention, we propose that future studies should further analyse also the potential role of astaxanthin and other essential carotenoids.

Parental investment and the economization of parenting

ABSTRACT We argue that economists, as well as other social scientists, have increasingly focused on parenting as a means of building children’s human capital and reducing poverty. This is reflected, in part, in the use of the concept of ‘parental investment’ to study parenting, which has gained prominence over the past thirty years. This intellectual program is also evident in interventions targeting low-income parents to change parenting behavior to reflect the ‘parental investment’ model. Our study first documents the rise of the use of ‘parental investment’ in economics, psychology, and sociology, using a SCOPUS-generated corpus of academic documents. Through a critical analysis of two highly influential articles, we uncover the key assumptions of the economic approach to the study of parenting. We then show how this approach informs parenting programs that directly affect parenting behavior. Finally, we offer preliminary reflections on the consequences of the economization of parenting.

High fat diet consumption and social instability stress impair stress adaptation and maternal care in C57Bl/6 dams

Poor maternal diet and psychosocial stress represent two environmental factors that can significantly impact maternal health during pregnancy. While various mouse models have been developed to study the relationship between maternal and offspring health and behaviour, few incorporate multiple sources of stress that mirror the complexity of human experiences. Maternal high-fat diet (HF) models in rodents are well-established, whereas use of psychosocial stress interventions in female mice are still emerging. The social instability stress (SIS) paradigm, serves as a chronic and unpredictable form of social stress. To evaluate the combined effects of a poor maternal diet and intermittent social stress on maternal health and behaviour, we developed a novel maternal stress model using adult female C57Bl/6 mice. We observed that all HF+ mice demonstrated rapid weight gain, elevated fasting blood glucose levels and impaired glucose tolerance independent of the presence (+) or absence (-) of SIS. Behavioural testing output revealed anxiety-like behaviours remained similar across all groups prior to pregnancy. However, integrated anxiety z-scores revealed a mixed anxious profile amongst HF+/SIS+ females prior to pregnancy. HF+/SIS+ females also did not show reduced plasma ACTH and corticosterone levels that were observed in our other HF+ and HF- stress groups after SIS exposure. Further, HF+/SIS+ females demonstrated significant postpartum maternal neglect, resulting in fewer numbers of live offspring. These findings suggest that prolonged maternal HF diet consumption, coupled with previous exposure to SIS, places a significant burden on the maternal stress response system, resulting in reduced parental investment and negative postpartum behaviour towards offspring.

How do school experiences in adolescence affect educational investment in adulthood? The case of parental investment in private tutoring in Germany

AbstractThis article examines the role of parents’ school experiences in adolescence on their educational investment strategies for their own children in middle adulthood. We focus our analysis on the parents’ decision to organize private tutoring (also called shadow education) for their children. Previous international research largely agrees that families with a high socioeconomic status (SES) are more likely to invest in tutoring to achieve competitive advantages in the educational race for higher credentials and maintain a high social status. In Germany, however, recent studies suggest that tutoring in Germany primarily serves underperforming children from les educated families to acquire relatively higher school degrees by compensating the higher demands of academic school tracks. We propose a theoretical decision model based on rational choice and life course theory incorporating psychological factors related to school performance of the parents (such as performance anxiety and ability self-concept) and operationalize four components that are intended to explain the (un)equal use of tutoring: (1) children’s school background, (2) parents’ cost and (3) benefit considerations, as well as (4) parents’ school biography. In addition, we hypothesize on the intergenerational transmission of performance-related factors from parents to their children and how this affects SE investment. We test our hypotheses quantitatively through logit regressions and a structural equation model using unique longitudinal data for 558 families (parents and their children) from the German “LifE” study (1979–2012). Our study produced two key findings: On the one hand, the parents’ previous school performance plays a direct role in the extent to which they themselves are able to provide their children with the necessary support in the event of poor performance. On the other hand, the performance-related experiences of the parents during school are to a certain extent transmitted to their children and thus influence their grades, ability self-concept and performance anxiety. These factors, in turn, are decisive for the decision to organize SE. Our findings indicate that instead of reducing the decision-making process for SE to absolute dimensions of student performance and parents’ SES and related cost-benefit calculations, dynamic factors behind this family decision related to intergenerational transmission and individual characteristics should be considered.

“Don't Touch!”: The Role of Cultural Knowledge in Low‐SES Parents' Perceptions of Museums

Museums can provide valuable benefits for children, but children from low socioeconomic (SES) backgrounds are less likely to have exposure to such institutions. We draw on interviews with 52 low‐SES parents to explore how perceptions of museums influence whether parents would consider bringing their children there. Respondents express a clear preference for enriching activities for their children. However, our findings reveal a tension between this general desire and parents' impressions of what museums are and how their children will experience them. We illustrate how limited familiarity with museums produces a circumscribed view of the range of experiences available at different kinds of museums and influences parents' perceptions of their child‐appropriateness, thus demonstrating the role of class‐based cultural knowledge in shaping the choices parents make about out‐of‐school activities. Our findings complicate the binary narrative that attributes parental investments to either preferences or resources and highlights how cultural knowledge about such activities may contribute to social inequality. The study also offers insights for cultural institutions that wish to attract a more socioeconomically diverse base of visitors.

Searching for mates may shape parental investment and immune response

Searching for mates may shape parental investment and immune response

The Difference of Parental Investment Model Between Multi-child Family and One-child Family

This study compared the parental investment patterns of multi-child families and single-child families. Through comparative analysis of the two family types, it is found that they have some differences in parental investment behavior. The results show that families with many children pay more attention to the cultivation of parent-child relationship, while families with only one child pay more attention to the cultivation of individual ability and independence. The research also found that the two kinds of families have differences in education investment, time investment and emotional investment, and different family types have their own characteristics and advantages in parental investment. These findings have important implications for understanding the differences in parental investment between different family types.

How Does Poverty Affect Primary School Achievement in Bangladeshi Children?The Mediating Role of Parental Investment and Parenting Practice

ABSTRACT The study examined whether monetary investment and parenting practices mediate the association between family and hardship and primary school achievement in a sample of Bangladeshi children (N = 1140; M age = 9.11, SD = .88 at baseline). The questionnaire method was used for data collection. The results from structural equation modeling suggested that although all factors partially mediated a predictor–outcome link, parenting practices explained a greater amount of variance in the associations with children’s poor achievement as compared with monetary investment after accounting for background factors. We discuss future directions for social policy and research.

Single Parent Efforts in Meeting Family Economic Needs in Bubu Village, Kambowa District, North Buton Regency

The purpose of the study is to find out how the efforts of single parents in fulfilling the exit economy of a single parent in Bubu Village, and to find out what are the supporting and inhibiting factors in an effort to meet the economic needs of the family in Bubu Village, Kambowa District, North Buton Regency. This type of research uses a qualitative approach with a problem study method to 8 single parents in Bubu Village.The data collection technique uses interview, observation, and documentation methods. Data analysis uses approaches, namely: data collection, data reduction, data presentation, and conclusion drawn. The results of this study show the efforts of single parents in meeting the economic needs of families in Bubu Village/sub-district, Kambowa District, North Buton, namely 1. Work, 2. Expecting help from family, 3. Expect help from the government. The supporting factors for single parent efforts to meet the economic needs of the family are, 1. Motivation and encouragement from the family. The factors that hinder single parent efforts in meeting the economic needs of the family are, 1. Limited skills, 2. Limited infrastructure, 3. There is no help from the husband in meeting the needs of the family

The female red jungle fowl (Gallus gallus gallus) reproductive investment stimulated by male attractiveness

Abstract. Lelono A, Riedstra B, Groothuis T. 2024. The female red jungle fowl (Gallus gallus gallus) reproductive investment stimulated by male attractiveness. Biodiversitas 25: 2931-2936. To maximize their capacity for reproduction, mothers are expected to modify their investment in offspring based on the quality of their mates. A recent study showed that females in female-care only species do so by investing more in egg mass when mated with attractive males rather than in other reproductive traits. In our study, we investigated how red jungle fowl (Gallus gallus gallus) mothers invest in clutch production based on the size of the male's comb, a trait signaling attractiveness. We randomly paired 14 females with 14 males of either large or small combs and monitored their egg laying, clutch completion, and brood rearing. Following the initial clutch, we exchanged male partners and permitted females to establish up second generation. We found that females who were partnered with males who had bigger combs laid down their eggs earlier after pairing compared to those paired with males with smaller combs. However, there were no variations in egg mass or clutch size that we could find. Furthermore, the size of the male's comb influenced the growth and body condition of female chicks, with those sired by males with larger combs being heavier and in better condition at twenty-four weeks old. These data support the premise of the positive Differential Allocation (DA) hypothesis, where maternal investment varies with mate quality, rather than the negative DA, where females more investment in offspring from lower quality mates.