Papers by Julianne Holt-Lunstad
Mothers in numerous species exhibit heightened aggression in defense of their young. This shift t... more Mothers in numerous species exhibit heightened aggression in defense of their young. This shift typically coincides with the duration of lactation in nonhuman mammals, which suggests that human mothers may display similarly accentuated aggressiveness while breast feeding. Here we report the first behavioral evidence for heightened aggression in lactating humans. Breast-feeding mothers inflicted louder and longer punitive sound bursts on unduly aggressive confederates than did formula-feeding mothers or women who had never been pregnant. Maternal aggression in other mammals is thought to be facilitated by the buffering effect of lactation on stress responses. Consistent with the animal literature, our results showed that while lactating women were aggressing, they exhibited lower systolic blood pressure than did formula-feeding or neverpregnant women while they were aggressing. Mediation analyses indicated that reduced arousal during lactation may disinhibit female aggression. Together, our results highlight the contributions of breast feeding to both protecting infants and buffering maternal stress.
Psychosomatic Medicine, 2007
Objective: To investigate if diurnal cortisol variation is associated with nocturnal blood pressu... more Objective: To investigate if diurnal cortisol variation is associated with nocturnal blood pressure (BP) dipping. Methods: In this study, 302 healthy adults (51% female; average age 31 years) underwent 24-hour ambulatory BP assessment with BP measured randomly approximately every 20 minutes during waking hours and every hour during sleep. Salivary cortisol was obtained at five time points. Cortisol and BP have natural diurnal variations and disruptions in these diurnal variations are related to pathological conditions, such as greater risk for cardiovascular disease. A lack of a drop in cortisol from day to night and a lack of a drop in BP from waking to sleeping have both been associated with negative outcomes. It is not known, however, if diurnal variations in cortisol and BP are related, or if changes in cortisol from day to night influence BP dipping. Results: Diurnal cortisol variation was a significant predictor of BP dipping. Controlling for gender, body mass index, age, phase of menstrual cycle, sleep quality, morning cortisol, and daytime measures of the relevant cardiovascular assessments did not significantly affect the results. Cortisol variation was found to have a stronger relationship with BP dipping than any of the covariates measured. Conclusion: Decreased diurnal variation in cortisol is associated with decreased diurnal variation in BP. Future studies could benefit from examining how these two variables interact in predicting disease outcomes.
Psychological Science, 2011
Mothers in numerous species exhibit heightened aggression in defense of their young. This shift t... more Mothers in numerous species exhibit heightened aggression in defense of their young. This shift typically coincides with the duration of lactation in nonhuman mammals, which suggests that human mothers may display similarly accentuated aggressiveness while breast feeding. Here we report the first behavioral evidence for heightened aggression in lactating humans. Breast-feeding mothers inflicted louder and longer punitive sound bursts on unduly aggressive confederates than did formula-feeding mothers or women who had never been pregnant. Maternal aggression in other mammals is thought to be facilitated by the buffering effect of lactation on stress responses. Consistent with the animal literature, our results showed that while lactating women were aggressing, they exhibited lower systolic blood pressure than did formula-feeding or never-pregnant women while they were aggressing. Mediation analyses indicated that reduced arousal during lactation may disinhibit female aggression. Toget...
Journal of Behavioral Medicine, 2011
Background: The quality and quantity of individuals ’ social relationships has been linked not on... more Background: The quality and quantity of individuals ’ social relationships has been linked not only to mental health but also to both morbidity and mortality. Objectives: This meta-analytic review was conducted to determine the extent to which social relationships influence risk for mortality, which aspects of social relationships are most highly predictive, and which factors may moderate the risk. Data Extraction: Data were extracted on several participant characteristics, including cause of mortality, initial health status, and pre-existing health conditions, as well as on study characteristics, including length of follow-up and type of assessment of social relationships. Results: Across 148 studies (308,849 participants), the random effects weighted average effect size was OR = 1.50 (95 % CI 1.42 to 1.59), indicating a 50 % increased likelihood of survival for participants with stronger social relationships. This finding remained consistent across age, sex, initial health status,...
Encyclopedia of Gerontology and Population Aging
Current Directions in Psychological Science
The influence of social relationships extends beyond emotional well-being to influence long-term ... more The influence of social relationships extends beyond emotional well-being to influence long-term physical-health outcomes, including mortality risk. Despite the varied measurement approaches used to examine social relationships within the health literature, the data can be synthesized using social connection as an organizing framework. This review discusses cumulative scientific evidence of links between various aspects of social connection and mortality, as well as supporting evidence for links with morbidity and plausible mechanisms. This evidence fulfills the criteria outlined in the Bradford Hill guidelines for establishing causality. Despite strong evidence currently available, several gaps remain and will need to be addressed if society is to rise to the challenge of developing effective interventions to reduce risk associated with social disconnection. This evidence has important broader implications for medical practice and public health.
International Journal of Environmental Research and Public Health
The COVID-19 global pandemic and subsequent public health social measures have challenged our soc... more The COVID-19 global pandemic and subsequent public health social measures have challenged our social and economic life, with increasing concerns around potentially rising levels of social isolation and loneliness. This paper is based on cross-sectional online survey data (available in 10 languages, from 2 June to 16 November 2020) with 20,398 respondents from 101 different countries. It aims to help increase our understanding of the global risk factors that are associated with social isolation and loneliness, irrespective of culture or country, to support evidence-based policy, services and public health interventions. We found the prevalence of severe loneliness was 21% during COVID-19 with 6% retrospectively reporting severe loneliness prior to the pandemic. A fifth were defined as isolated based on their usual connections, with 13% reporting a substantial increase in isolation during COVID-19. Personal finances and mental health were overarching and consistently cross-cutting pre...
Public Policy & Aging Report
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, Jan 23, 2018
Previous studies reveal that oxytocin (OT) encourages prosocial behavior in humans; however, anim... more Previous studies reveal that oxytocin (OT) encourages prosocial behavior in humans; however, animal studies and recent work in humans suggest that OT may also play a role in aggressive behavior and feelings. The present study investigated these competing predictions in the context of a competitive task among 85 healthy human participants (males and females). Using a randomized double-blind design, participants were assigned to an experimental (intranasal OT) or control (intranasal placebo) group. Hostility (Aggression Questionnaire) was measured at home (T1) and in the lab after intranasal administration (T2). Behavioral aggression was assessed post-intranasal administration. There was a significant difference between the OT and the placebo group on hostility scores (p = 0.03) and a significant time by group interaction for behavioral aggression (p < 0.05). Self-reported hostility was significantly higher at T2 compared to T1 (p < 0.001) among participants in the oxytocin grou...
American Psychologist
A robust body of scientific evidence indicates that being embedded in high-quality close relation... more A robust body of scientific evidence indicates that being embedded in high-quality close relationships and feeling socially connected to the people in your life is associated with decreased risk for all-cause mortality as well as a range of disease morbidities. Despite mounting evidence that the magnitude of these associations is comparable to many leading health determinants (that receive significant public health resources), government agencies, healthcare providers and associations, and public/private healthcare funders are slow to recognize human social relationships as either a health determinant or health risk marker in a manner that is comparable to other public health priorities. This article evaluates current evidence (on social relationships and health) according to criteria commonly used in determining public health priorities. The piece discusses challenges for reducing risk in this area and outlines an agenda for integrating social relationships into current public health priorities.
The Psychology of Friendship, 2016
Current Opinion in Psychology, 2017
This paper reviews the research on relationships and mental health. Individuals who are more ment... more This paper reviews the research on relationships and mental health. Individuals who are more mentally healthy are more likely to select into relationships, but relationships are also demonstrably associated with mental health. The type of relationship matters - evidence suggests that more established, committed relationships, such as marriage, are associated with greater benefits than less committed unions such as cohabitation. The association between relationships and mental health is clearly bidirectional, however, stronger effects are observed when mental health is the outcome and relationships are the predictor, suggesting that the causal arrow flows more strongly from relationships to mental health than vice versa. Moreover, improving relationships improves mental health, but improving mental health does not reliably improve relationships. Our review of research corroborates the view that relationships are a keystone component of human functioning that have the potential to influence a broad array of mental health outcomes.
Behavioral Sleep Medicine, 2016
For most adults, sleep is a dyadic behavior. Only recently have studies explored the dynamic asso... more For most adults, sleep is a dyadic behavior. Only recently have studies explored the dynamic association between sleep and relationship functioning among bed partners. The current study is the first to examine bidirectional associations between changes in insomnia and changes in marital quality over time, in the context of a marital therapy trial. Among husbands, improvements in marital satisfaction were associated with a 36% decreased risk of insomnia at follow-up. Regarding the reverse direction, counter-intuitively, wife baseline insomnia was associated with improvements in husbands&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; marital satisfaction, but only among the non-treatment-seeking comparison group. Results are discussed in terms of implications for sleep and marital therapy, and suggest that improving sleep may be an added benefit of improving the marital relationship.
Journal of Social and Personal Relationships, 2014
Prior studies report that couples with higher relationship quality show higher oxytocin (OT) leve... more Prior studies report that couples with higher relationship quality show higher oxytocin (OT) levels, yet other studies report those with higher distress have increased OT. This study investigated these competing predictions in the context of a support enhancement intervention among 34 young married couples ( N = 68). Preintervention marital quality (Dyadic Adjustment Scale) was examined for associations with plasma and salivary OT levels 4 weeks apart and for changes between these time points within the intervention group. High relationship quality, not distress, was associated with higher OT in both saliva and plasma at both time points. No significant interaction was found between marital quality and intervention condition; relationship quality and support intervention were both independently associated with higher postintervention OT levels.
Perspectives on psychological science : a journal of the Association for Psychological Science, 2015
Actual and perceived social isolation are both associated with increased risk for early mortality... more Actual and perceived social isolation are both associated with increased risk for early mortality. In this meta-analytic review, our objective is to establish the overall and relative magnitude of social isolation and loneliness and to examine possible moderators. We conducted a literature search of studies (January 1980 to February 2014) using MEDLINE, CINAHL, PsycINFO, Social Work Abstracts, and Google Scholar. The included studies provided quantitative data on mortality as affected by loneliness, social isolation, or living alone. Across studies in which several possible confounds were statistically controlled for, the weighted average effect sizes were as follows: social isolation odds ratio (OR) = 1.29, loneliness OR = 1.26, and living alone OR = 1.32, corresponding to an average of 29%, 26%, and 32% increased likelihood of mortality, respectively. We found no differences between measures of objective and subjective social isolation. Results remain consistent across gender, len...
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 2014
The protective influence of social relationships on health is well documented; however, not all r... more The protective influence of social relationships on health is well documented; however, not all relationships are positive and negative aspects of relationships may be detrimental. Relatively less is known about the relationships characterized by both positivity and negativity (i.e., ambivalence). The goal of this study was to examine the relative influence of ambivalence in relationship quality and social behavior on cardiovascular response. 104 healthy young adults were randomly assigned to bring in either a supportive or ambivalent same-sex friend to the experiment. Participants were also randomly assigned to receive positive, negative, ambivalent or ambiguous feedback from their friend after giving a series of speeches. Cardiovascular response was obtained before, during, and after the social stressor (speech task). Results indicate a significant effect of relationship type before, during, and after the stressor task. Adjusting for baseline, heart rate reactivity and anxiety was...
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Papers by Julianne Holt-Lunstad