Developmental psychobiology最新文献

Social support is associated with positive health outcomes and may be protective during sensitive life periods. Importantly, biological factors, including hormones, are associated with psychological and interpersonal functioning, but less is known about the link between biological factors and perceived social support during the transition to parenthood. The current study examined prenatal testosterone levels as a predictor of postpartum perceived social support among first-time parents. Participants (N = 110 husband–wife dyads) engaged in an ecologically valid laboratory-based infant simulator task involving an inconsolable doll. Saliva samples were collected prenatally before and after the infant simulator task. Perceived social support was self-reported prenatally and at 6 months postpartum. On average, fathers’ baseline testosterone levels were higher than mothers’ (p < 0.001). Most fathers and mothers demonstrated an increase in testosterone in response to the parenting task (n_fathers = 66; n_mothers = 67). An actor–partner interdependence model tested the association of prenatal baseline testosterone and testosterone reactivity predicting postpartum perceived social support, accounting for prenatal perceived social support. Findings revealed that (1) lower mother prenatal baseline testosterone was associated with higher mother postpartum perceived social support and (2) lower father prenatal testosterone reactivity was associated with higher mother postpartum perceived social support. No paths predicted fathers’ postpartum perceived social support. Interpretations and implications of these findings are discussed.

Depressed mothers often experience parenting difficulties, which can persist after their symptoms have remitted. However, not all depressed mothers show parenting struggles, suggesting that there could be unidentified characteristics that increase risk. Specifically, neurobiological models emphasize that reward system deficits contribute to maladaptive parenting and depression, but no studies have evaluated how they could conjointly lead to parenting challenges. This study focused on event-related potential (ERP) components, the reward positivity (RewP), and feedback negativity (FN), which assess neural responsiveness to reward and loss feedback, respectively. Mothers with (n = 81) and without (n = 55) depression histories completed a monetary reward task to elicit the FN and RewP, and depression and parenting questionnaires. We found mothers demonstrating a blunted FN to loss and increased depressive symptoms reported greater authoritarian parenting, whereas there was no association between depressive symptoms and authoritarian parenting among mothers exhibiting greater neural loss responsiveness. Furthermore, these effects were specific to maternal current depressive symptoms and not major depressive disorder (MDD) diagnostic history. Maternal depressive symptoms were associated with reduced warmth, but the RewP did not moderate this association. Together, findings suggest that depressed mothers with blunted responsiveness to negative cues may be particularly vulnerable to adopt authoritarian parenting styles.

Social buffering may reduce the persistent impacts of acute early life stress (aELS) and, thus, has important implications for anxiety- and trauma-related disorders. First, we assessed whether aELS would induce maladaptive fear incubation in adult mice, a PTSD-like phenotype. Overall, animals showed incubation of fear memory in adulthood, independent of aELS condition. Next, we investigated whether social interaction with the dam and/or the littermates following the aELS session would eliminate adult fear incubation. Males demonstrated social buffering only if the dam was present, and females demonstrated social buffering only if the littermates were present. Finally, we assessed whether social buffering following aELS exposure reduces consolidation of the associative fear learning that occurs during the aELS session. Animals received aELS followed by isolation or social interaction (dam + littermates). Over the next four consecutive days, they received 30-min exposures to the context (test/extinction). There were no differences between isolation and social interaction on contextual fear memory expression or its extinction. Taken together, these results indicate that social buffering reduces the impact of nonassociative processes during aELS on subsequent adult fear memory in a sex-dependent manner and further supports social buffering as an important intervention following early trauma experiences.

Adolescent male rodents and humans exhibit impairments in extinguishing learned fear. Here, we investigated whether female adolescent rats exhibit such impairments and if extinction is affected by the estrous cycle as in adults. Following fear conditioning to a discrete cue, female adolescent Sprague Dawley rats were extinguished either around the onset of puberty, when estrous cycling begins, or across different stages of the estrous cycle. Both extinction retention and renewal (a form of relapse) were assessed. Peri-pubertal females had comparable freezing during extinction training and tests of extinction retention and fear renewal as age-matched males. They were noted to generally be in metestrus, a low estradiol phase, at extinction training. Postpubertal females that received extinction training in proestrus (high estradiol phase), but not metestrus (low estradiol phase), had lower freezing during extinction training and retention than males; males exhibited more freezing during a renewal test than both groups of females. Our findings suggest that female adolescent rats have reduced fear during extinction training and retention compared to males only when extinguished in a high-estradiol phase. These findings suggest fear inhibition fluctuates across the estrous cycle in adolescence, and estradiol may protect females against impairments in fear extinction during this developmental period.

Parental incarceration can be stressful for children, leading to less optimal development. Although parental incarceration typically takes place among other adversities, resilience processes occur in many families, for example, in instances of secure child–caregiver attachment relationships. Yet, it is not known how secure attachments are associated with stress processes in children with incarcerated parents, especially in the context of other risks. The current study analyzed data from 67 child–caregiver dyads, measuring cumulative stress hormones (cortisol and cortisone) through children's hair samples and assessing attachment security using the Attachment Q-sort. Results indicated that children with higher attachment security scores had lower levels of cortisone and the combined cortisol/cortisone variable, aligning with the Learning Theory of Attachment, which posits that secure attachments mitigate stress through consistent, supportive caregiving. Conversely, children with insecure attachments exhibited more extreme cortisone levels, suggesting dysregulated stress responses. These findings underscore the importance of attachment security as a resilience factor in children facing parental incarceration and other adversities. The study calls for targeted interventions to strengthen caregiver–child relationships, which could buffer the long-term negative impacts of chronic stress. These results highlight the need for family-related approaches to support the well-being of children affected by mass incarceration.

This preregistered study investigated whether human paternal testosterone levels predicted fathers’ time spent with their child and their involvement in childcare and household tasks. Additionally, we examined whether associations were mediated by fathers’ attitudes toward child gender stereotypes. Associations were tested in an exploratory sample (n = 70, M = 6.73 months postpartum, SD = 2.13) and a test sample (n = 80, M = 2.67 months postpartum, SD = 0.77). Testosterone was quantified from the 1-cm hair segments closest to the scalp. Fathers reported on the amount of time spent with their child and on their attitudes toward child gender stereotypes. Mothers and fathers reported on fathers’ involvement in childcare and household tasks. In the exploratory sample, testosterone levels were positively associated with involvement in childcare and household tasks but unrelated to the time spent with the child. In the test sample, testosterone levels did not predict the time spent with the child or involvement in childcare and household tasks. In both samples, no evidence was found for mediation by attitudes toward child gender stereotypes. In conclusion, testosterone levels are differently but not systematically associated with involvement in childcare and household tasks during the first year of fatherhood.

The adaptive calibration model (ACM) asserts that the stress response system, including the parasympathetic nervous system (PNS), conditionally adapts to one's environment. In infancy, the proximal context of parental influences (e.g., maternal depression/anxiety) affects the development of the infant stress response system. In contrast, the relation between broader contexts, such as neighborhood environment, and infant PNS development is less well understood, despite the impact neighborhoods may have on maternal mental health and youth outcomes. The present study bridges prior research examining relations between neighborhood and maternal depression, and maternal depression and infant PNS development. Latent growth curve analysis with mother–infant dyads (N = 320), assessed when infants were 4, 8, 12, 18, and 24 months old, indicated that maternal depressive symptoms showed global decreases across infancy and that infant resting RSA showed global increases, as well as variability across the sample in these trajectories. Moderated mediation modeling showed significant direct effects of neighborhood structural disadvantage on initial levels of infant resting RSA. However, there were no significant indirect effects of neighborhood through maternal depressive symptoms on RSA levels or trajectories. These findings suggest that the broader environment impacts infant stress response system development, but this may occur through other mechanisms beyond proximal maternal depressive symptoms.