Parental Investment Research Articles

The systematic variation in relative brain size among vertebrate classes remains poorly understood. Here, based on the expensive brain hypothesis, we propose that two broad constraints explain much of the variation: 1) the ability to produce large offspring, and so provide them with the energy required for constructing larger brains, and 2) the ability to sustain continuously high body temperatures, because cooler and varying brain temperatures reduce brain performance and thus fitness. We therefore predicted that encephalization (major evolutionary increases in brain size) only happened where changes in physiology or natural history created these abilities. First, comparative analyses across all major vertebrate classes (n = 2600 species) revealed that protecting or provisioning eggs or embryos is associated with larger newborns. Subsequent analyses at the class level confirmed that newborn size and adult brain size underwent correlated evolution in birds, mammals, and cartilaginous fishes, but not in other fishes, amphibians, and reptiles. Second, we found a positive relationship between mean body temperature and brain size within each class (albeit sometimes insignificant). Third, a combined analysis across all vertebrates revealed a positive interaction between the effects of body temperature and newborn size. In conclusion, encephalization became most pronounced in vertebrate lineages that can both produce large offspring, reflecting internal fertilization with matrotrophy, and sustain high body temperature, partly linked to endothermy.

Oxytocin and the Pace of Life History Strategies: From Evolutionary Trade-Offs to Translational Pathways.

Age-appropriate preventive care and continuous health management are essential for maintaining health in children and adolescents. This study aimed to investigate the effects of regular well-child follow-up from birth on physiological and psychosocial characteristics during adolescence. Adolescents aged 9-21 who presented to an Adolescent Health Outpatient Clinic (AHOC) for follow-up were stratified into two groups based on their longitudinal follow-up from birth until they commenced attendance at the AHOC. The first group consisted of adolescents whose child health follow-ups were conducted at the Well-Child Outpatient Clinic (WCOC) under the concept of social paediatrics (Group 1). The second group consisted of adolescents whose child health follow-ups were conducted by family physicians at family health centres but were not followed up at the WCOC (Group 2). A comparison of the groups was conducted using data recorded during their initial assessments at the AHOC retrospectively. These data included anthropometric measures, psychosocial assessments (using the HEEADSSS screening tool), immunisation status and laboratory findings. All data analyses were performed using IBM SPSS v.28, with a significance level set at p < 0.05. Group 1 comprised 51.5% (n = 138), while Group 2 comprised 48.5% (n = 130). The study revealed no statistically significant differences in terms of gender or parental sociodemographic characteristics. The average age at data retrieval was found to be 10.1 years in Group 1 and 11.5 years in Group 2. This indicated that Group 1 exhibited a significantly younger average age. Additionally, Group 2 demonstrated significantly higher weight- and BMI-based SDS and a higher prevalence of anaemia. Subsequent analysis revealed no statistically significant differences in lipid values or height SDS. Group 2 exhibited a higher prevalence of psychosocial risks, including risks related to the home environment, educational attainment, dietary habits and suicide risk. Structured regular child health follow-up from birth has been demonstrated to have a positive impact on adolescent health and well-being. This phenomenon persists irrespective of parental socioeconomic status, encompassing both physiological and psychosocial dimensions. However, observed variations may also be indicative of unmeasured parental health-seeking behaviours, health literacy and investment. Consequently, the interpretation of results should be approached with a degree of caution.

Highly educated individuals have their first child at later ages compared to less-educated individuals, and parental investment is associated with the childbearing of adult children. However, no studies have explored the association between maternal and paternal investment and the timing of parenthood for adult daughters and sons, and whether this association varies by education level. Based on the parenthood penalty and life-history theory, it is hypothesized that parental investment decreases the age at first birth of highly educated adult children and increases the age at first birth of less educated and those currently enrolled in education, particularly between mothers and adult daughters. Event-history analyses were conducted on 4,111 participants and 894 first births from 13 waves of the longitudinal and population-based German Family Panel Analysis of Intimate Relationships and Family Dynamics Study (Pairfam). Results show that contact with mothers was associated with earlier parenthood in less-educated adult children and later parenthood in highly educated adult children. However, contact with fathers was associated with later parenthood in currently enrolled adult children and earlier parenthood in highly educated adult sons. Europe's fertility decline is largely due to delayed age at first birth and parental investment in adult children can contribute to and counteract this trend.

Nestling feeding in altricial birds is a physiologically demanding phase of the annual cycle. Accordingly, parental effort in breeding songbirds has been suggested to be limited by the maximum capacity to perform sustained aerobic work. However, the maximum capacity for exercise and plasticity thereof is understudied in free-living, breeding songbirds. We tested two predictions related to the plasticity of exercise capacity in breeding blue tits with increasing workload due to an increasing demand for nestling feeding as nestlings grow older and with experimentally increased brood size. We measured the maximum exercise-induced metabolic rate and endurance of parents both early on and at the peak of nestling feeding, and found that exercise capacity increases with nestling age. Parents of enlarged broods had higher exercise capacity than those with unmanipulated broods, but this was only true for young birds. We suggest that the exercise capacity of breeding birds is a plastic trait and depends on the amount of exercise that has been performed in the preceding days. However, the potential for an increase in exercise capacity is likely to be affected by parental age and experience, behavior, resource availability, in addition to nestling age and brood size.

Parents of children newly diagnosed with autism report higher parenting stress levels than parents of typically developing children. Parent-mediated interventions include parents as interventionists in their child's intervention but often require increased parent effort and time to engage in the intervention. We investigated the influence of a parent-mediated early intervention for autistic children, the Bridge Skill Development Program, on parenting stress and child outcomes. Thirty-eight families of autistic children completed the Parenting Stress Index-4th Edition-Short Form (PSI-4-SF) at pre- and post-intervention. We used paired-samples t tests and linear regressions to examine the effects on intervention outcomes and parenting stress on program outcomes. Controlling for mastered pre-intervention skills, children demonstrated significant improvements in core skills from pre- to post-intervention (t(37) = 6.81, p < .001). Parents reported significant pre- to post-intervention reduction in parental distress (t(37) = -2.53, p = .008), parent-child dysfunction (t(37) = -4.03, p < .001), parents' perception of their child's difficult behavior (t(37) = -1.94, p = .03), and overall parenting stress (t(37) = -3.34, p < .001). Results suggest that families benefitted from this parent-mediated intervention, regardless of pre-intervention parenting stress levels, and intervention participation increased child skill development without increasing parenting stress.

Sex determination is essential for the life history of sexually reproducing organisms. Understanding the mechanism behind sex determination decisions, however, is not trivial, as processes such as random meiosis can shape the sex of the offspring besides environmental conditions. Haplodiploid organisms are relatively unconstrained from these internal influences: Males develop from unfertilized and females from fertilized eggs. Females can thus base sex allocation on their individual parental expenditure and account for the prevalent environmental conditions they live in. We aim to disentangle the influence of environmental conditions on sex determination and resource allocation decisions of haplodiploid organisms (population sex ratio, individual sex allocation probability, individual resource allocation and foraging efficiency). For this, we studied the European orchard bee (Osmia cornuta) at a high spatial and temporal resolution in a quantitative field study. We applied a recently developed camera system and deep-learning-based evaluation toolset that allowed us to analyse over 1000 pollen collection flights (food provisioning for offspring) and over 800 clay collection flights (nest-building material) to test whether sex determination and resource allocation in haplodiploid organisms depend on environmental conditions. Contrary to expectations based on established sex determination theories, the overall population sex ratio and individual offspring resource allocation were independent of environmental conditions. Individual sex allocation probability, however, shifted with flower cover, connectivity of seminatural habitat, temperature and progressing season. Pollen and clay collection durations, proxies for foraging efficiency, were not influenced by available resources in the landscape. Instead, pollen collection efficiency decreased with higher temperatures and clay collection efficiency decreased with lower temperatures and progressing season (both represented by increasing flight durations). A short-term insurance strategy may explain the diverse influences of environmental conditions on individual sex allocation probability, whereas long-term bet-hedging might result in consistent offspring resource allocation and population sex ratio within a year, with potential carry-over effects into the next generation. We therefore conclude that sex determination is not monocausal and that nest-provisioning females might pursue multiple aims at the same time. We emphasize the importance of long-term data to further unravel the sex determination mechanisms of sexually reproducing organisms.

The marsupial pouch is a key adaptation for offspring protection and development, yet its evolutionary drivers remain unclear. While body size matters, the role of litter size is less understood. Using phylogenetic comparative methods, we investigated the evolutionary relationship between pouch presence, body mass, and litter size across 195 marsupial species. Our results reveal that pouch presence is strongly phylogenetically conserved and positively correlated with larger body size, with all large-bodied species possessing a pouch. By contrast, pouch presence is negatively associated with litter size, with species with larger litters typically lacking a pouch, while those with smaller litters retain one. We found that body mass evolves faster in pouched lineages. Ancestral state reconstructions suggest multiple independent origins of the pouch, although the ancestral marsupial condition remains uncertain, but most likely corresponding to pouch absence. These findings support the hypothesis that the pouch evolves in response to trade-offs between offspring quantity and maternal investment, aligning with broader patterns of parental care strategies. Our work provides a new vision for the evolutionary trajectory of one of the most conspicuous marsupial features.

The purpose of this study was to test the roles of ethnic and racial identity (ERI) processes and autonomy-supportive parenting on college students' psychological adjustment. American college students of color (N = 505) completed questionnaires assessing ERI exploration and commitment, autonomy-supportive parenting, and psychological adjustment (self-esteem, depressive symptoms). Key variables were operationalized as latent constructs, and main and interaction effects were tested using the latent moderated structural equation modeling approach. Higher levels of ERI commitment (but not exploration) and parental autonomy support each uniquely predicted higher levels of self-esteem and lower levels of depressive symptoms. Parental autonomy support moderated associations between ERI processes and psychological adjustment, and the nature of moderation did not differ across Black and Latino/a/x students. Supporting the psychological adjustment of college students of color necessitates acknowledging the importance of both parental and institutional efforts to encourage students' autonomy strivings and ERI processes. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Abstract Parental care behaviour has strong fitness consequences and has been widely studied, but variation in the effort that species invest in warming young has been neglected. Here, we investigate the extent and possible causes of variation in brooding, or warming, effort among 90 species of altricial birds on four continents. We measured parental warming effort based on the percentage of time parents spent warming young for the first approximately 6 h of each day over the entire nestling period of each species. Our measure of warming behaviour was based on 62,249.5 h of video data over 10,770 video days from 4482 nests. We calculated the initial magnitude of effort at the start of the nestling period and the rate that effort declined with the age of the nestlings. Higher initial magnitude and slower rates of decrease reflected higher effort. We found that brooding behaviour varied extensively among species. Brooding effort was greater in species in which both parents shared the effort and those with greater energy reserves from larger body size, indicating effort is under energetic limitation. Brooding effort was substantially lower in enclosed‐nesting species than in those using open‐cup or cavity nests, consistent with predictions that enclosed nests better retain heat and reduce parental energy demand of warming. Effort was not simply related to thermal demands. Brooding effort increased with the number of young in the brood, opposite to expectations based on greater thermal inertia. Instead, the increase in warming effort with the number of young in the brood fits with life history predictions of those species being under selection for greater reproductive effort. Understanding how the costs and benefits of brooding effort interact with other evolved traits is essential for advancing parental investment and life history theory. Read the free Plain Language Summary for this article on the Journal blog.

ABSTRACT This paper presents a psychoanalytic reflection regarding one’s identity (selfhood) based on the case of a young woman in a situation of social vulnerability. We aim to highlight the relevance of Freud’s and Ferenczi’s theories in understanding the dynamics of narcissism and object relations in clinical psychoanalysis, offering a solid basis for investigating selfhood. The analysis of the clinical case raised fundamental questions about psychic development and the importance of early object relations. First, we explored the concept of narcissism and the parental figures’ role in the constitution of the infant psyche. We reiterate that narcissistic problems arise when the parental libidinal investment is not sufficient, affecting the subject’s ability to differentiate between the self and the other. Our reflection on selfhood, drawn from the clinical vignette, was mainly based on texts by Freud and Ferenczi to show how parents’ lack of affection and care can cause lasting dysfunctions in subjective functioning. An “unwelcome child” can internalize feelings of undesirability and inadequacy, resulting in low self-esteem and exacerbated self-criticism throughout life. These factors profoundly impact the construction of subjectivity and have repercussions on relationships throughout life, including the analytical relationship. We acknowledge the significance of external validation in constructing the self and the indispensable role of a compassionate and authentic approach in engaging with the patient. It fosters the strengthening of the bond and the development of trust in oneself and the therapeutic process by acknowledging the validity of the patient’s emotions and perceptions.

HighlightsWhat are the main findings?Parent and teacher differences in perceptions of young children’s behavior regarding desire for knowledge, confidence, talkativeness, good-naturedness, and understanding are negatively associated with at least one key developmental metric (social, concentrative, general knowledgeability, linguistic, and mathematical).Parent and teacher differences in perceptions of a child’s behavior regarding neatness are positively associated with all five developmental metrics.What is the implication of the main finding?Differences in how parents and teachers perceive child behavior are significantly associated with the development of children’s social and cognitive abilities compared to their peers. Aligning parent and teacher perceptions of children may help children reach developmental milestones in a timely manner.Background/Objectives: Time spent with parents and educators encompasses a large portion of a child’s waking hours, with the home and early childhood education and care serving as two of the first settings in which children develop social and cognitive abilities. While previous studies have used social and cognitive tests to examine antecedents of child behavior, we extend such studies to take into account the congruence and incongruence of parents’ and teachers’ views on those antecedents. We examine the importance of parent-teacher alignment on the perceptions of a child’s personality and abilities in early development. Methods: Parents and teachers of 2968 German Kindergarten-aged (4–5 years old) children were surveyed using the National Educational Panel Study (NEPS). Parents and teachers independently rated 10 child behavioral traits, with higher scores indicating more prosocial behavior. Educators also rated children on five developmental abilities (social abilities, ability to concentrate, language abilities, general knowledgeability, and mathematical reasoning) compared to the student’s peers. While previous work has often examined how parental investments in children or teachers’ views of children might be related to development, we provide a new take by examining parents and teachers in conjunction with each other. Research that has looked at both parents and teachers has tended to examine alignment, or lack thereof, on child behaviors and personality traits. We analyzed child developmental abilities using OLS regression models, measures of parent–teacher divergences in ratings of child behavior, and demographic controls. Results: Greater differences in parent and teacher perceptions of desire for knowledge were negatively associated with all five developmental abilities. Differences in parent and teacher perceptions on talkativeness, confidence, good-naturedness, and understanding were negatively associated with at least one developmental outcome. By contrast, differences in perceptions of children’s neatness were positively associated with all five developmental abilities. Conclusions: Using both parent and teacher perceptions of child behaviors and abilities is a unique approach to understanding the relevance of parent and educator perceptions to a child’s development. Our findings indicate the need for collaboration across young children’s home and school or care settings. Establishing congruence in perceptions and the kinds of relationships that can lead to such congruence can help children with behavioral issues receive support in both home and educational settings and encourage mutual respect and partnership between parents and educators.

Life history theory posits negative trade-offs between current reproduction and survival and between current and future reproduction. We tested if the Saffron Finch (Sicalis flaveola), a sexually dichromatic thraupid with age-related plumage coloration, conforms to the expectations under this theory. Previous studies in nest-box systems have shown that both drab young males and bright-yellow older males provide similar parental care and achieve comparable reproductive success. We experimentally handicapped females and males from both age classes by clipping of three primary remiges to manipulate their parental care efforts. We compared mating pairs conformed by handicapped males of both age classes paired with non-handicapped females, handicapped females paired with either handicapped or non-handicapped males of both age classes, against control pairs (non-handicapped individuals). We assessed weight changes, feeding rates, brooding bout duration, nest temperature, and return rates for both adults and nestlings, as well as growth rate, asymptotic weight, time spent at the nest, and fledgling success. Contrary to expectations, none of the experimental individuals adjusted their feeding rates. However, we observed intra- and intergenerational costs for handicapped females mated to second-year males, including shorter brooding bouts, greater weight loss, slower offspring growth, and lighter fledglings. Thus, in our study system, lower-quality females paired with second-year males may be maximizing reproductive success under less-than-ideal circumstances.

Real-time context-dependent cooperation in parental provisioning reveals fitness payoffs in barn owls

Parental investment, peer interaction, and children's depression: Evidence from nationally representative panel data in China.

SynopsisParental care and territoriality are crucial components for the success of avian reproduction. Biparental care with female-biased efforts prevails in avian species, whereas breeding territories in most birds are male- or bisexual-defended. In social-polyandrous birds, however, females trade parental care for mating through sex-role reversal. On the other hand, managing multiple broods or mating events exposes females to physiological/environmental constraints of energetic-nutritional demands, which in turn may result in variations in egg mass and subsequent egg fates. This study assessed sexual differences in parental efforts, including territoriality, time allocation of parental behaviors, and egg-laying (reflected by egg mass) in sex-role-reversed pheasant-tailed jacanas, Hydrophasianus chirurgus, and their relationships with brood success. Females monopolized small ponds but shared larger ones with female neighbors by holding larger territories. In contrast, male territories were within those of their mates, the size was not affected by the presence of male neighbors, and was associated with the total hatchlings and fledglings obtained through multiple clutches. The time allocated in parental behaviors differed between the sexes and across the pre-laying, incubation, and post-hatching stages. The breeding duration, territory size, female breeding order, and male mating order, however, had no effects on parental time allocation. While male time spent chick-attending was positively correlated with brood success, preening negatively correlated with the fledging rate, other behaviors had no effects on reproductive outputs. The egg mass varied slightly, but showed no effect of year, nor the season of laying date until late August. The fourth egg in a clutch was lighter and, among clutches, the egg mass tended to be greater in later clutches and clutches from polyandrous females. We found positive correlations between mean egg mass and the numbers of hatchlings and fledglings gained per clutch. Our results suggest a substantial pre-laying parental input through egg production in polyandrous females. Brood success, however, appears to be determined by the combined effects of multiple factors, including male devotion and environmental conditions.

The Trivers-Willard Hypothesis posits that parents in favorable conditions tend to invest more in male offspring, while those in disadvantaged conditions focus on female offspring under the disadvantaged condition based on the reproductive potential of the next generation. Through a review of previous studies, we find that these series of studies lack a unified measurement to assess parental socioeconomic status and parental investment, which may be the cause of inconsistent results. To solve this problem, our study establishes a cross-culturally applicable measurement framework. By measuring the annual household income, the income distribution ratios and time investment differences between children of different sexes, we aim to validate the Trivers-Willard Hypothesis. Even if there are possible negative results in future studies, our measurement still contributes to enhancing methodological homogeneity in future research.

The relationship between parental investment and high school students' academic achievement: The mediating role of academic emotions and the moderating role of learning motivation.

Parents respond diversely to their children’s LGBTQ+ identity and coming out, engaging in emotionally charged moments characterized by a broad spectrum of feelings and reactions. These responses are deeply influenced by parental values, cultural norms, and religious beliefs. This article offers a contemporary-historical perspective on the efforts of American Jewish parents with LGBTQ+ children to advocate for their inclusion within both Jewish communities and broader society. Through textual analysis of various pioneering and current initiatives such as viral petitions and letters to rabbis, it is inferred that their call for recognition of their children’s LGBTQ+ identity is understood as a religious commandment and an important strategy for preserving the continuity and integrity of the Jewish community. The use of rhetoric, language, and religious rituals helps them justify and persuade others of the equal place of their LGBTQ+ children within contemporary Jewish communities. Thus, I conclude that their efforts to foster open, LGBTQ+-affirming parental dialogue demonstrate how the struggle for LGBTQ+ recognition can intersect with religious perspectives and values. Their advocacy plays a significant role in advancing LGBTQ+ inclusion, particularly through the adoption and promotion of egalitarian religious narratives and discourse.

This study determines the involvement of parents in decision-making regarding the academic achievement of students as perceived by secondary school teachers. In order to obtain an accurate and better understanding on the study, a quantitative-descriptive survey research design was employed using a survey-questionnaire that focused on the parents’ involvement in decision-making regarding the academic achievement of students in terms of: a) supervising child’s homework, b) observed and identifies the need of the children, and c) participates in their children’s literacy process. The respondents were the thirty (30) teachers from secondary departments of Mindanao State University- Lanao National College of Arts and Trades. The results were tabulated using statistical tools such are: frequency, percentage distribution and weighted mean. It very undeniably that it is very important for students to excel in their academic studies, parents’ involvement is the great factor that influence students’ peak performance in academe. The results revealed that students’ motivation is necessary for their academic achievement because it provokes students to persevere through challenges, eventually succeed. On the problem in supervising students’ homework conveyed that parents had established a tone in monitoring their child’s home works with a mean of 2.6. The results further implied that parents have greater extent involvement in their children’s academic achievement. Likewise, on observed and identify the need of the children, it was perceived into “always” with mean of 2.7. The results express the parents understanding on the needs of their children. They recognized and monitor the developmental breakthrough of their children. Besides, participate in their children’s literacy process was regarded the efforts of parents to maximize the development of their children’s literacy. The results recognized the parents’ involvement in decision-making regarding the academic achievement of the students was directly correlates to their children’s academic success. While parents’ involvement on students’ performance is understood, the purpose is to sustain the learning, not to replace the students strive and responsibility.