Exploring the links between dispositions, romantic relationships, support networks and community inclusion in men and women

Reading the Mind in the Eyes Test Scores Demonstrate Poor Structural Properties in Nine Large Non-Clinical Samples

The Reading the Mind in the Eyes Test (RMET) is widely used in clinical and non-clinical research. However, the structural properties of RMET scores have yet to be rigorously examined. We analyzed the structural properties of RMET scores in nine existing datasets comprising non-clinical samples ranging from 558 to 9,267 (median = 1,112) participants each. We used confirmatory factor analysis to assess two theoretically derived factor models, exploratory factor analysis to identify possible alternative factor models, and reliability estimates to assess internal consistency. Neither of the theoretically derived models was a good fit for any of the nine datasets, and we were unable to identify any better fitting multidimensional models. Internal consistency metrics were acceptable in six of the nine datasets, but these metrics are difficult to interpret given the uncertain factor structures. Our findings contribute to a growing body of evidence questioning the reliability and validity of RMET scores.

Why friendship and loneliness affect our health

Humans, like all monkeys and apes, have an intense desire to be social. The human social world, however, is extraordinarily complex, depends on sophisticated cognitive and neural processing, and is easily destabilized, with dramatic consequences for our mental and physical health. To show why, I first summarize descriptive aspects of human friendships and what they do for us, then discuss the cognitive and neurobiological processes that underpin them. I then summarize the growing body of evidence suggesting that our mental as well as our physical health and wellbeing are best predicted by the number and quality of close friend/family relationships we have, with five being the optimal number. Finally, I review neurobiological evidence that both number of friends and loneliness itself are correlated with the volume of certain key brain regions associated with the default mode neural network and its associated gray-matter processing units.

Social network investment of men: Cross-sectional and longitudinal associations with mental health problems

Internationally, there is growing attention on links between social isolation and mental health problems. Here, we use unique Australian longitudinal data to investigate associations between adult men's (n = 507; age M = 29.90, SD = 1.31) social network investments and their concurrent and subsequent mental health problems. In linear regressions, using generalised estimating equations (GEEs), we examined associations between social network investment (time with friends, network size and various activities with friends) and mental health symptoms (depression, anxiety and stress) across five timepoints. Models were adjusted for waves of outcome and potential confounders. Cross-sectionally, each social network investment variable, except for drinking with friends, was negatively associated with depressive symptoms. Men's extended friendship network size and sharing a meal with friends were negatively associated with concurrent anxiety and stress. Time spent and physical activity with friends was also negatively associated with concurrent stress. In longitudinal analyses, after adjusting for prior depressive symptoms, only the number of friends in close and extended networks remained protective against depressive symptoms 1 year later. Results did not differ by fatherhood or relationship status. Programs designed to strengthen men's investment in social networks are recommended to reduce men's depressive symptoms.

Social isolation and the brain in the pandemic era

Intense sociality has been a catalyst for human culture and civilization, and our social relationships at a personal level play a pivotal role in our health and well-being. These relationships are, however, sensitive to the time we invest in them. To understand how and why this should be, we first outline the evolutionary background in primate sociality from which our human social world has emerged. We then review defining features of that human sociality, putting forward a framework within which one can understand the consequences of mass social isolation during the COVID-19 pandemic, including mental health deterioration, stress, sleep disturbance and substance misuse. We outline recent research on the neural basis of prolonged social isolation, highlighting especially higher-order neural circuits such as the default mode network. Our survey of studies covers the negative effects of prolonged social deprivation and the multifaceted drivers of day-to-day pandemic experiences.

Laughter influences social bonding but not prosocial generosity to friends and strangers

Humans deploy a number of specific behaviours for forming social bonds, one of which is laughter. However, two questions have not yet been investigated with respect to laughter: (1) Does laughter increase the sense of bonding to those with whom we laugh? and (2) Does laughter facilitate prosocial generosity? Using changes in pain threshold as a proxy for endorphin upregulation in the brain and a standard economic game (the Dictator Game) as an assay of prosociality, we show that laughter does trigger the endorphin system and, through that, seems to enhance social bonding, but it does not reliably influence donations to others. This suggests that social bonding and prosociality may operate via different mechanisms, or on different time scales, and relate to different functional objectives.

Social complexity and the fractal structure of group size in primate social evolution

Compared to most other mammals and birds, anthropoid primates have unusually complex societies characterised by bonded social groups. Among primates, this effect is encapsulated in the social brain hypothesis: the robust correlation between various indices of social complexity (social group size, grooming clique size, tactical behaviour, coalition formation) and brain size. Hitherto, this has always been interpreted as a simple, unitary relationship. Using data for five different indices of brain volume from four independent brain databases, we show that the distribution of group size plotted against brain size is best described as a set of four distinct, very narrowly defined grades which are unrelated to phylogeny. The allocation of genera to these grades is highly consistent across the different data sets and brain indices. We show that these grades correspond to the progressive evolution of bonded social groups. In addition, we show, for those species that live in multilevel social systems, that the typical sizes of the different grouping levels in each case coincide with different grades. This suggests that the grades correspond to demographic attractors that are especially stable. Using five different cognitive indices, we show that the grades correlate with increasing social cognitive skills, suggesting that the cognitive demands of managing group cohesion increase progressively across grades. We argue that the grades themselves represent glass ceilings on animals' capacity to maintain social and spatial coherence during foraging and that, in order to evolve more highly bonded groups, species have to be able to invest in costly forms of cognition.

Loneliness-based impaired reward system pathway: Theoretical and clinical analysis and application

Loneliness is a key determinant in the etiology of mental health disorders such as depression and has profound impacts on health, quality of life, and economic productivity. This narrative review uses extant neurobiology and evolutionary literature to propose a construct through which loneliness may induce depression in adulthood via the reward system (including symptom and treatment aspects). Early childhood (distal) factors were found to be important in influencing adult (proximal) factors, which lead to the formulation of the construct. Due to the heterogenous and comorbid nature of depression, a new subtype known as 'reward depression' was distinguished along with distinct symptoms to aid practitioners when assessing patient treatment options. Furthermore, an evolutionary perspective was applied to the current impaired reward construct to discuss how the ancestral purpose and environment (in terms of reward) clashes with the modern one. Finally, theoretical treatment and prevention ideas were examined and discussed, leading into future work that needs to build upon and confirm the outlined construct.

Navigating the choppy waters to Nirvana: A critical reflective account of caring for ageing parents in the fourth age

This article revisits a paper and from an autoethnographic/critical reflective biographical approach re-examines seven cultural notions or myths, which may encourage ageism. It is framed within my experiential knowledge of caring for my ageing parents, with the tensions and challenges around problematising the value of expertise based on experience, communication, grief, and autonomy and freedom versus safety. The commentary emphasises that by analysing the impact of our personal life experiences, we can start to understand both the intended and unintended consequences of policy and practice affecting those in the fourth age. As a social work educator, I wanted to reflect upon how my tacit experiential knowledge, if made explicit, could impact upon my own and others’ learning. The recent death of my father has allowed for a period of reflection on my own caring and indeed my professional social work experience, knowledge, skills and practice. It is argued that the ageing process is unequal as class and socio-economic factors, i.e. geography, age, gender, religion and ethnicity, all play parts in determining how someone ages, and indeed upon the care an individual older person receives. A fuller understanding of negotiating the role of one stakeholder, that of a family carer in the ageing process, is elicited in this paper.

Chronic social isolation exerts opposing sex-specific consequences on serotonin neuronal excitability and behaviour

Social isolation raises the risk for mood disorders associated with serotonergic disruption. Yet, the underlying mechanisms by which the stress of social isolation increases risk are not well understood. Men and women are differently vulnerable; however, this modulating role of sex is challenging to study in humans under carefully controlled conditions. Therefore, we investigated this question in mice of both sexes, asking how the long-term stress of social isolation (from weaning into adulthood) affects the excitability of serotonin neurons in the dorsal raphe nucleus as well as mouse behaviour. The electrophysiological experiments and the first set of behavioural tests were conducted in young adult mice, with additional behavioural assays completed as the mice matured to assess the stability of their behavioural phenotype. We found that social isolation exerted seemingly-opposite effects in male and female mice, relative to their respective group-housed littermate controls. This distinctive pattern was observed for the effect of social isolation on the control of serotonergic neuron excitability via the SK family of calcium-activated potassium channels. Furthermore, we observed a similar and consistent pattern on tests relevant to assessing the efficacy of anti-depressant medicines, including the forced swim test, the novelty-suppressed feeding test, and the sucrose preference test. These findings underscore the concept that stress-elicited illness manifests distinctly in males and females and that treatments aimed at restoring serotonergic function may require a sex-specific approach. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.

Genetic Influences on Social Relationships: Sex Differences in the Mediating Role of Personality and Social Cognition

Objectives

In humans (and primates more generally), evolutionary fitness arises by two separate routes: conventional reproduction build around dyadic relationships and, reflecting the processes of group augmentation selection, how well individuals are embedded in their community. These processes are facilitated by a suite of genetically inherited neuroendocrines and neurotransmitters. It is not, however, known whether these effects are directly due to genetic factors or are mediated by aspects of personality, or whether there are sex differences in the way this is organised.

Methods

We examine whether dispositional factors related to the processing of social information, such as personality (Big 5 and Impulsivity), attachment style (Anxious and Avoidant dimensions) and sociocognitive capacity (emotion recognition) mediate associations between variation in receptor genes for oxytocin, vasopressin, beta-endorphin, dopamine, serotonin, testosterone and two core social relationship indices (the Sociosexual Orientation Index [SOI] and Support Network size).

Results

In men, variation in dopamine genes indirectly influences SOI through its effect on Impulsivity. In contrast, in women, variation in endorphin and vasopressin genes independently affect Openness to Experience, which mediates indirect effects of these genes on SOI. Moreover, endorphin gene variation also impacts on Network Size in women (but not men), via Extraversion.

Conclusions

These findings reveal that dispositional aspects of personality mediate some genetic effects on behaviour, thereby extending our understanding of how genetic and dispositional variation interact to determine individual differences in human sexual and social cognition and behaviour. The differences between the sexes seem to reflect differences in the two sexes’ social strategies.