Everyday co-presence with a romantic partner is associated with lower C-reactive protein.

Social relationships are an important driver of health, and inflammation has been proposed as a key neurobiological mechanism to explain this effect. Behavioral researchers have focused on social relationship quality to further explain the association, yet recent research indicates that relationship quality may not be as robust a predictor as previously thought. Here, building on animal models of social bonds and recent theory on close relationships, we instead investigated merely being in the physical presence of one's romantic partner. Specifically, we tested the hypothesis that spending more time co-present with a loved partner in everyday life would be associated with lower C-reactive protein (CRP). Three times over the course of one month, 100 people in romantic relationships reported how much time they spent in the same physical space as their partner in the prior 24 h, in minutes, and provided a sample of blood for CRP assay (n observations = 296). Results from multi-level models showed that when one reported spending more time in the physical presence of their partner they had lower CRP - an effect that was independent from social relationship quality explanations from the prior literature, including romantic relationship quality, hostility, and loneliness. These findings move past global assessments of social isolation to consider a novel everyday behavior that is of great interest in the non-human animal literature - spending time together -- as a potential mechanism linking high-quality relationships and physical health in adult humans. The findings also point to future research on additional behavioral mechanisms that are not dependent on stress pathways: people in high-quality relationships tend to spend enjoyable and affectionate time with one another, which may impact inflammation.

The roles of inflammation, affect, and interoception in predicting social perception.

"Sickness behavior" is an orchestrated suite of symptoms that commonly occur in the context of inflammation, and is characterized by changes in affect, social experience, and behavior. However, recent evidence suggests that inflammation may not always produce the same set of sickness behavior (e.g., fatigue, anhedonia, and social withdrawal). Rather, inflammation may be linked with different behavior across contexts and/or across individuals, though research in this area is under-developed to-date. In the present study (n = 30), we evaluated the influence of affective context and individual differences in difficulty detecting bodily sensations (i.e., interoceptive difficulty) on social perception following an inflammatory challenge. Inflammation was induced using the influenza vaccine and inflammatory reactivity was operationalized as changes in circulating levels of interleukin-6 (IL-6) before the vaccine and approximately 24 h later. Twenty-four hours after administration of the influenza vaccine, we manipulated affective context using a well-validated affect misattribution task in which participants made trustworthiness judgments of individuals with neutral facial expressions following the rapid presentation of "prime" images that were positive or negative in affective content. Interoceptive difficulty was measured at baseline using a validated self-report measure. Results revealed significant interactions between inflammatory reactivity to the influenza vaccine and affective context on social perception. Specifically, individuals with greater inflammatory reactivity were more biased by affective context when judging the trustworthiness of neutral faces. In addition, interoceptive difficulty and affective context interacted to predict social perception such that individuals with greater interoceptive difficulty were more biased by affective context in these judgments. In sum, we provide some of the first evidence that inflammation may amplify the saliency of affective cues during social decision making. Our findings also replicate prior work linking interoceptive ability to the use of affect-as-information during social perception, but in the novel context of inflammation.

Inflammatory reactivity to the influenza vaccine is associated with changes in automatic social behavior.

Recent evidence suggests differential patterns of social behavior following an inflammatory challenge, such that increases in inflammation may not uniformly lead to social withdrawal. Indeed, increases in inflammation have been associated with enhanced self-reported motivation to approach a specific close other, and greater neural sensitivity to positive social cues. However, no known studies have examined the association between inflammation in response to an inflammatory challenge and social behavior in humans, nor has past research examined specifically how approach and withdrawal behavior may differ based on whether the target is a close other or stranger. To address this, 31 participants (ages 18-24) received the influenza vaccine to elicit a low-grade inflammatory response. The morning before and approximately 24 h after the vaccine, participants provided a blood sample and completed a computer task assessing automatic (implicit) approach and withdrawal behavior toward a social support figure and strangers. Greater increases in the inflammatory cytokine interleukin-6 (IL-6) in response to the vaccine were associated with an increase in accuracy in avoiding strangers and a decrease in accuracy in approaching them. Increases in IL-6 were also associated with a decrease in reaction time to approach a support figure, but only when controlling for baseline IL-6 levels. There were no associations between change in IL-6 and changes in self-reported motivation to engage in social behavior with either close others, or strangers. Together, these findings reveal that increases in inflammation following the influenza vaccine are associated with automatic social behavior, especially behavior suggesting avoidance of unfamiliar social targets and ease in approaching a support figure. These data add to the growing literature suggesting that the association between inflammation and social behavior includes both social withdrawal and social approach, depending on the specific target.

Higher interleukin-6 is associated with greater momentary social connection in close relationships in daily life.

Recent evidence has documented associations between higher levels of inflammation and social approach behaviors toward close others in laboratory-based tasks. Yet it is unknown if this translates to interactions with close others in daily life. Given that momentary experiences of social connection have both relational and health consequences, this is a critical gap in our knowledge. To address the association between inflammation and momentary social connection experiences in close relationships, 55 participants provided blood samples on two consecutive days, which were assayed for circulating levels of the inflammatory marker interleukin-6 (IL-6). After providing the first blood sample, participants received the annual influenza vaccine as a mild inflammatory challenge. Participants also reported on cognitive, affective, and behavioral indicators of social connection with a specific close other multiple times across the two study days. Results indicated that levels of IL-6 were positively associated with temporally-proximal indicators of momentary social connection with a close other. Specifically, higher levels of IL-6 were associated with greater feelings of comfort from the close other, greater desire to be near them, and higher reported relationship quality. Greater IL-6 reactivity to the vaccine was only associated with increased reported relationship quality. These data add to the existing literature suggesting that higher levels of IL-6 may motivate social approach toward a close other, extending evidence to now include momentary social connection experiences in daily life.

The Basic Psychological Need Satisfaction and Frustration Scales probably do not validly measure need frustration.

In basic psychological needs theory (BPNT), the separable constructs of need satisfaction and need frustration are theorized as pivotally related to psychopathology and broader aspects of well-being. The Basic Psychological Need Satisfaction and Frustration Scales (BPNSFS; Chen et al., 2015) have rapidly emerged as the dominant self-report measure in the BPNT domain, with translated versions available in a wide range of languages and a plethora of versions adapted for specific populations and life contexts. Through (a) an extended conceptual discussion of the BPNSFS and (b) a collection of complementary data analyses in eight samples, we demonstrate that the BPNSFS probably does not validly measure need frustration. Most importantly, we conclude that the ostensible distinction between need frustration and need satisfaction in the BPNSFS is likely primarily a method artifact caused by different item keying directions, given the way the measure currently assesses the intended constructs. If so, then the use of the BPNSFS may be generating misleading conclusions, obstructing sound investigation of current BPNT. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Perceived Partner Responsiveness Forecasts Behavioral Intimacy as Measured by Affectionate Touch.

Affectionate touch is an important behavior in close relationships throughout the lifespan. Research has investigated the relational and individual psychological and physical benefits of affectionate touch, but the situational factors that give rise to it have been overlooked. Theorizing from the interpersonal process model of intimacy, the current studies tested whether perceived partner responsiveness forecasts affectionate touch in romantic couples. Following a preliminary integrative data analysis (N = 842), three prospective studies use ecologically valid behavioral (Studies 1 and 2) and daily (Studies 2 and 3) data, showing a positive association between perceived partner responsiveness and affectionate touch. Furthermore, in Study 3, we tested a theoretical extension of the interpersonal process of intimacy, finding that affectionate touch forecasts the partner's perception of the touch-giver's responsiveness the next day. Findings suggest affectionate touch may be an untested mechanism at the heart of the interpersonal process of intimacy.