Background: These two studies examined whether facial expressions in student identification photographs were connected with health care center visitation. Method: In Study 1, participants (N = 267) completed a short online survey that detailed the number of times they had visited a health care center in the last year. In Study 2, participants (N = 435) answered this same question, but health care center visits were divided into four categories: illness, injury, mood-related, and preventive. In both studies, the photographs on participants’ student identification cards were coded as no smile, non-Duchenne smile, or Duchenne smile. Results: Logistic regressions revealed that in Study 1, participants with non-Duchenne or Duchenne smiles were more likely to have visited a health care center in the past year than participants with no smile in their photograph. However, Study 2 revealed that this finding was driven by preventive health care center visits: participants with non-Duchenne or Duchenne smiles in their photographs were more likely to have visited a health care center in the past year for preventive purposes than participants with no smile in their photograph. No facial expression differences were found for health care center visits for illness, injury, or mood-related concerns. Conclusions: Smiling in photographs is connected to preventive health care center visits, a positive health behavior. Future research should continue to investigate whether smiles in photographs are connected with other important health outcomes

Background: Emotional well-being and the quality of the parent-child bond are robust predictors of cardiovascular functionality and stress responses, and thus may have important implications for health outcomes. The aim of the current study is to assess whether positive emotional exchanges (i.e., emotion coregulation) within the mother-child dyad play a protective role in children’s stress responses. Specifically, we test whether positive emotion coregulation among mothers and their preschool-aged children is associated with children’s respiratory sinus arrhythmia (RSA; a marker of heart rate variability) at rest or over the course of a stressful experience. Method: One hundred mother-child dyads (Mchildage = 3.5 years) participated in a standardized laughing task in which positive emotional constructs were measured. Children also participated in a frustration task without the mother present while RSA was continuously monitored. Results: Hierarchical linear regressions revealed that greater mother positive emotional response to child was associated with child baseline and stress recovery RSA, but not with children’s RSA during the frustrating task. Exploratory analyses reveal that this effect is partially due to mother, but not child, overall positivity. Findings held in serial analyses in which we controlled for children’s overall positive affect (PA) and children’s positive affect (PA) in response to mothers but not when we controlled for mother’s overall PA. Conclusion: Positive emotion coregulation is associated with children’s resting RSA as well as RSA recovery from a frustrating task.

Smartphones are often vilified for negatively influencing well-being and contributing to stress, but these devices may also be potentially used in positive ways to aid in stress recovery. Despite the vast potential afforded by smartphones, this topic has rarely been studied in experimental stress research and little is known about whether smartphones can alter recovery trajectories following a stressful experience. Thus, this dissertation investigates the psychological and physiological effects of utilizing smartphones in differing ways following the experience of an acute laboratory stressor. Specifically, this dissertation examines how having a phone present, using a phone freely, or using a guided application on a smartphone influences stress recovery. To examine this issue, an experiment was conducted in which participants underwent a social-evaluative laboratory stressor and then were left alone to recover in a specific way depending on condition. Those in the no phone condition did not have access to their phone. Those in the phone present condition had a phone in their possession but were restricted from using it. Those in the phone use condition could use their phone freely. Those in the guided phone use condition used an application that delivered heart rate variability biofeedback training. Psychological and physiological stress recovery was assessed via repeated measures of salivary alpha amylase and self-reported stress. Results indicated that those in the guided phone use condition had significantly steeper physiological recovery trajectories than those in the phone present and no phone conditions. The phone use and guided phone use conditions did not differ. No differences were found in regard to self-reported stress. In addition, mediation analyses were conducted to investigate mechanisms of interest based on a series of planned comparisons. Neither distraction, perceived social support, positive affect, negative affect, nor feelings of calm were found to be significant mediators. Therefore, no tested mechanisms explaining found effects were conclusively determined. From these results, it can be concluded that engaging in a brief biofeedback training session on a smartphone can effectively reduce physiological stress levels. Overall, this dissertation provides evidence to shed light on how, when, and why smartphones influence stress recovery.

Smiling has been shown to be beneficial in a number of social situations. One context in which smiling has not been well researched, however, is within physical health and health-relevant outcomes. The small amount of research in this area has found that smiling may buffer the cardiovascular effects of acute pain. The goals of this dissertation were to 1) investigate smiling in the context of physical and social pain and 2) examine potential mediators (orbicularis oculi activation in Study 1 and positive affect in both studies) that may underlie the connections between smiling and acute pain. In Study 1, participants were randomly assigned to make Duchenne (genuine) smiles, grimaces, or neutral facial expressions during two acute physical pain tasks. Cardiovascular responses (heart rate, respiratory sinus arrhythmia, and pre-ejection period) were measured at baseline, during the tasks, and after the tasks. Pain threshold, pain tolerance, and self-reported pain were also measured. Results showed that trajectories across cardiovascular variables of interest did not significantly differ between the facial expression conditions. There were also no significant differences in pain tolerance or self-reported pain among the conditions. However, participants who made Duchenne smiles during the cold pressor had significantly higher pain threshold levels than participants who made grimaces, although there were no differences between either of these groups and the neutral facial expression condition. Furthermore, some evidence was found to support PA and orbicularis oculi activation as mediators of smiling and outcome variables. In Study 2, participants were randomly assigned to make Duchenne smiles or neutral facial expressions while they were included or excluded during Cyberball, a task that has been found to reliably elicit feelings of social exclusion. Results showed that participants who made Duchenne smiles while being excluded from Cyberball had significantly different heart rate trajectories than participants who were making neutral facial expressions. There were no differences in respiratory sinus arrhythmia, pre-ejection period, or self-reported pain between conditions. No evidence was found for positive affect as a mediator between smiling and outcome variables. Taken together, these studies provide some evidence that smiling during physically or socially painful situations might be beneficial.

Objectives: Mobile phones are increasingly becoming a part of the social environment, and when an individual feels excluded during a socially stressful situation, they often retreat to the comfort of their phone to ameliorate the negativity. Thus, this study tests whether smartphone presence does in fact alter psychological and physiological responses to a social stressor. Methods: Participants (N = 148) were subjected to a peer exclusion stressor. Prior to exclusion, participants were randomized to one of three conditions: (1) phone present with use encouraged, (2) phone present with use restricted, or (3) no phone access. Saliva samples and self-report data were collected throughout the study to assess salivary alpha amylase (sAA), cortisol, and feelings of exclusion. Results: Participants in both phone-present conditions reported lower feelings of exclusion compared to individuals who had no access to their phone, p=.005. Reported exclusion was not significantly different between phone-present groups. Multi-level modeling of sAA responses revealed that the individuals in the restricted phone condition had a significantly different trajectory following the stressor compared to the phone use condition (p=.032) and no phone condition (p=.008). Specifically, those in the restricted phone condition showed a decrease in sAA following exclusion, those in the no phone condition showed a gradual increase, and phone users exhibited little change. Cortisol did not respond to the stressor. Conclusions: Taken together, these results suggest that the mere presence of a phone (not necessarily phone use) can reduce feelings of exclusion and buffer against the stress of social exclusion.

How do cultural values influence individual responses to stress in the context of experimentally-induced pain? A substantial literature has found ethnic differences in pain whereby ethnic minority groups (e.g., Latinos) report experiencing more pain and less willingness to endure pain during standardized pain tasks in the laboratory setting. However, little is known about the role Latino culture plays in the context of this type of pain. The goals of this dissertation were to examine simpatía, a Latino cultural value emphasizing reduced negative expressions during negative interactions and increased positive expressions during positive interactions, in the context of experimentally-induced pain. Specifically, this dissertation examined 1) whether simpatía was associated with pain (measured via self-report, tolerance, and physiological response) and 2) whether state emotions, emotional expressions, or vagal tone explained the association of simpatía with pain in Latinos. Additionally, this dissertation explored the role ethnic background played in this context as well. To induce pain, a standardized cold pressor task was used with water held at five degrees Celsius. Results indicated that, contrary to hypotheses linking simpatía to improved pain through its association with positive emotion, simpatía was instead associated with worse pain. Specifically, Latinos high in simpatía self-reported greater pain, were more likely to withdraw early from pain, and exhibited a flatter heart rate recovery slope compared with Latinos low in simpatía. However, no mediator significantly explained the simpatía-pain association and this association did not hold in European Americans. Taken together, the findings of this dissertation provide evidence for the importance of context in examining the influence of cultural values on the experience of acute physical pain.

Positive and negative affect has been associated with numerous health factors. However, what is commonly investigated are the mean levels of affect. While means reveal important information, how affect varies over time may provide further information about how the experience of affect relates to important outcomes. This change from moment to moment, day to day, or week to week has been referred to as affect variability and is often operationally defined as the standard deviation of affect over time. While useful, this methodology is incomplete as it loses important information about the temporal aspect of affect variability (i.e., information about patterns of affect responses over time are lost). Nevertheless, greater affect variability has been associated with several psychological health and health-relevant outcomes such as low self-esteem and higher depressive symptoms. What remains unclear is how affect variability patterns and interactions with mean levels relate to such variables. What is also unknown is whether affect variability is associated with markers of physical health. Therefore, the goals of this dissertation are to 1. assess whether affect variability is associated with markers of physical health, 2. examine a new method for assessing affect variability that may overcome the downsides of standard deviation (i.e., loss of information about patterns), and 3. use this new method to better understand how affect variability patterns relate to mental and physical health and health-relevant variables.

Microbes were the first organisms to evolve on Earth, and inhabit every known environment, including the human gut. Diverse microbial ecosystems are involved in a number of crucial bodily processes including educating the immune system. Interestingly, human microbiome composition and function is also linked to central nervous system activity, specifically, the stress response. Extant literature exploring the stress-microbiome connection in healthy, human adult samples is sparse and primarily tests these links in non-human animals or in clinical human samples, particularly those with depression and anxiety. This dissertation is among the first to explore stress-microbiome links across three stress domains in two samples of healthy adults, specifically, perceived stress, stressful life events, and cardiovascular function surrounding stress as indexed by Respiratory Sinus Arrhythmia (RSA). This vital next step will help researchers better understand the nuanced, dynamic connections between stress types and microbial composition.We carried out two main studies: Study 1 includes 62 healthy adults, 68% female with a mean age of 37.3 years and Study 2 includes 74 healthy women with a mean age of 41.6 years. Participants completed surveys assessing stressful life events, perceived stress and completed a laboratory stressor. RSA was collected prior to, during, and following a laboratory stressor. Following the laboratory visit, participants were given fecal collection kits to collect microbiome samples that were assayed for microbial composition. In Study 1, the low perceived stress group was higher in alpha diversity than the high perceived stress group. Both Study 1 and Study 2 revealed differences in beta diversity between stressful life events groups and Study 1 revealed differences in beta diversity between RSA stress reactivity groups. Differentially abundant microbes between groups are discussed. Further, levels of Clostridium were negatively associated with RSA stress reactivity in Study 1 and levels Escherichia/Shigella were positively associated with perceived stress in Study 2. Together, these studies show that stress group membership was differentially linked to microbial composition and that objective assessments of potentially severe stressors such as stressful life events may be more reliably linked to microbial composition (beta diversity) than subjective evaluations of perceived stress. This work provides a foundation for future research that should focus on experimental studies and longitudinal interventions designed to determine bidirectional links between stress types, bacterial species, and metabolic output.

Is the Superwoman Schema (SWS) health deleterious or health beneficial, and do specific aspects play a role? The Superwoman role has demonstrated negative relations to mental health. However, limited research has investigated the Superwoman role in the context of physical health. Studies that have investigated the physiological repercussions of the Superwoman Schema have been mixed, showing differential impacts of the different dimensions of the Superwoman role. The goals of this dissertation were to examine the Superwoman Schema, which posits that African American women are naturally strong, resilient, and nurturing, shaping the way they experience and interact with the world, and associations between SWS with stress, positive psychological resources, and cardiovascular health. Specifically, this dissertation examined 1) whether the overall SWS and the SWS dimensions were associated with cardiovascular health, 2) whether increased stress burden explain the relation between the SWS and SWS dimensions and cardiovascular health, and 3) whether positive psychological resources buffered the negative aspects of the SWS or enhanced the positive aspects of the SWS on cardiovascular health. Results indicated that contrary to hypotheses, the overall SWS was not associated with cardiovascular health outcomes on its own and stress was not a mediator of SWS and any of the cardiovascular health outcomes. However, three SWS dimensions (i.e., obligation to present an image of strength, motivation to succeed, and obligation to help others) did interact with positive psychological resources in association with nighttime diastolic blood pressure (DBP). At high levels of positive psychological resources, greater endorsement of obligation to present an image of strength, motivation to succeed, and obligation to help others was associated with lower nighttime DBP, while less endorsement of each of these SWS dimensions was linked with higher nighttime DBP. Several individual measures of positive psychological resources (i.e., environmental mastery, optimism, and resilience) also showed significant interactions with either SWS or at least one of the SWS dimensions on indices of cardiovascular health (i.e., pulse wave velocity, nighttime DBP, and combined intima-media thickness). At low levels of mastery, greater SWS endorsement was associated with higher pulse wave velocity, while less SWS endorsement was associated with lower pulse wave velocity. For those high in optimism, greater obligation to present an image of strength was linked with higher nighttime blood pressure, while less obligation to present an image of strength was linked with lower nighttime blood pressure. For those low in optimism and resilience, respectively, greater obligation to care for others was linked with increased intima-media thickness, while less obligation to care for others was linked with less intima-media thickness. Taken together, these findings suggest the importance of assessing the different components of the SWS and how they relate to stress and positive psychological resources to better understand how these factors may relate to health disparities for Black women.