Human beings are inextricably linked to others. The ties we share with other people throughout the lifespan are a fundamental aspect of our existence. It follows that any decision we make as individuals has the potential to affect others, including those closest to us. This notion that our decisions frequently have consequences for others has fascinated psychologists for decades. Recently there has been a resurgence of interest in the psychological community on the subject of social decision-making, defined as decisions that have some kind of implicit or explicit social consequence. This surge has carried with it an unprecedented understanding of social decision-making behaviors, yet social decision-making studies are frequently constrained by a lack of ecological validity, specifically in terms of social decision partners (e.g., pairing participants with strangers, confederates, or fictive individuals). Doing so means that much of the literature may not be applicable to the most frequent and impactful decisions humans make: those involving close others. I aimed to help resolve these limitations in this dissertation. Across three studies I examined social decision preferences between parents and friends, two developmentally important relationships, at the behavioral, neural, and cognitive levels. Study 1 shows that, overall, adolescents appear to exhibit a distinct preference towards parents over friends when making social decisions involving conflicting outcomes for these two close others. Study 2 expands this work by showing that value-based neural representations of these close others is associated with behavioral preference; Study 3 continues this conceptual line of work by broadening the scope to show that value-based cognitive representations—derived from naturalistic text data—are also linked to behavioral social decision preferences. The contributions of this work towards broader theories of social decision-making, developmental science, and social neuroscience are discussed.

Early life adversity impacts more than half of youth worldwide and is thought to contribute to a third of adult mental illness. In particular, early caregiving adversity (ECA) – including exposure to abuse, neglect, or circumstances surrounding placement in institutional or foster care – has profound consequences for socioemotional, cognitive, and behavioral development, and is a potent contributor to later psychopathology. While ECA research has focused on high-level cognitive and socioemotional capabilities crucial to preventing psychopathology, preliminary work in children suggests that ECA may also elevate risk for lower-level sensory processing challenges. Across three multi-method studies, this dissertation introduces consistent evidence that diverse forms of severe early caregiving adversity increase risk for sensory processing challenges that persist beyond early childhood into adolescence and young adulthood, and furthermore suggests that these sensory symptoms may contribute to the development of mental health challenges across populations. Study 1 found that two rare but profound categories of ECA are associated with elevated parent-reported sensory processing challenges in children and adolescents, and that these in turn are linked to elevated internalizing and externalizing symptoms. Study 2 showed that self-reported adversity-linked sensory challenges (and the same accompanying associations with internalizing symptoms) are present following experiences of more prevalent forms of ECA (e.g., neglect, abuse), persisting into adulthood. In addition, this study evaluated three candidate neurodevelopmental mechanisms that may contribute to the emergence of these sensory processing challenges, indicating affective and regulatory processes may be particularly important to consider in the context of enduring sensory symptoms. Lastly, Study 3 extended these findings, reporting elevated recruitment of prefrontal regulatory regions during aversive sensory stimulation in youth with histories of caregiving institutionalization, and providing novel evidence for the importance of regulatory experiences in the development and persistence of sensory processing challenges following ECA. Taken together, these studies advance developmental models of ECA by pointing to the importance of sensory processing as an underexplored and potentially tractable facet of development that may be critical to long-term mental health.

Early life adversity (ELA) is a potent and common risk factor for a number of mental health challenges. ELA is thought to increase risk for psychopathology in part by sensitizing threat-responsive neural circuitry and heightening vigilance to potential threat. This hypervigilance is thought to result in a tendency to overestimate threat in the face of ambiguity or uncertainty, a core feature of several internalizing disorders. However, few studies have examined how ELA shapes neural or behavioral responses to ambiguous and uncertain stimuli. Across three studies, this dissertation integrates neuroimaging, behavioral, and self-report data to examine how ELA shapes responses to ambiguity and uncertainty. We examine these associations in children, adolescents, and emerging adults with varying histories of caregiving adversity. In Study 1 and Study 2, we use representational similarity analysis to evaluate whether similarity in neural representations of ambiguity and threat varies depending on adversity history. In Study 1, we find that emerging adults who experienced higher levels of abuse and neglect demonstrate greater representational similarity between ambiguous and threatening stimuli within threat-sensitive neurocircuitry. These results indicate that ELA may predispose an individual to represent ambiguity as threatening at the neural level. In Study 2, we sought to replicate these findings in a population of adopted youth who had experienced institutionalization in orphanage care, a rare and extreme form of caregiving adversity. However, we find that the degree of similarity in neural representations of ambiguity and threat does not significantly differ between previously institutionalized and control youth. In Study 3, we demonstrate that emerging adults who experienced higher levels of abuse and neglect exhibit less avoidance of uncertainty in an explore-exploit task. Together, these three studies provide novel insights into how ELA shapes neural and behavioral functioning in the face of the unknown and how these processes relate to wellbeing following caregiving adversity.