The Moderating Role of Social Network Size on Social Media Use and Self-Esteem: An Evolutionary Mismatch Perspective

Existing meta-analyses have shown that the relationship between social media use and self-esteem is negative, but at very small effect sizes, suggesting the presence of moderators that change the relationship between social media use and self-esteem. Employing principles from social comparison and evolutionary mismatch theories, we propose that the social network sizes one has on social media play a key role in the relationship between social media use and self-esteem. In our study (N = 123), we showed that social media use was negatively related to self-esteem, but only when their social network size was within an evolutionarily familiar level. Social media use was not related to self-esteem when people’s social networks were at evolutionarily novel sizes. The data supported both social comparison and evolutionary mismatch theories and elucidated the small effect size found for the relationship between social media use and self-esteem in current literature. More critically, the findings of this study highlight the need to consider evolutionarily novel stimuli that are present on social media to better understand the behaviors of people in this social environment.

Contrasting effects of Western vs. Mediterranean diets on monocyte inflammatory gene expression and social behavior in a primate model

Dietary changes associated with industrialization substantially increase the prevalence of chronic diseases, such as obesity, type II diabetes, and cardiovascular disease, major contributors to the public health burden. The high prevalence of these chronic diseases is often attributed to an 'evolutionary mismatch' between human physiology and modern nutritional environments. Western diets enriched with foods that were scarce throughout human evolutionary history (e.g., simple sugars and saturated fats) promote inflammation and disease relative to diets more akin to ancestral human hunter-gatherer diets, such as a Mediterranean diet. Peripheral blood monocytes, precursors to macrophages and important mediators of innate immunity and inflammation, are sensitive to the environment and may represent a critical intermediate in the pathway linking diet to disease. We evaluated the effects of 15 months of whole diet manipulations mimicking human Western or Mediterranean diet patterns on monocyte polarization using a well-established model of human health, the cynomolgus macaque (Macaca fascicularis). Monocyte transcriptional profiles differed markedly between the two diets, with 40% of transcripts showing differential expression (FDR < 0.05). Monocytes from Western diet consumers were polarized toward a more proinflammatory phenotype. Compared to the Mediterranean diet, the Western diet shifted the co-expression of 445 gene pairs, including small RNAs and transcription factors associated with metabolism and adiposity in humans, and dramatically altered behavior. For example, Western-fed individuals were more anxious and less socially integrated compared to the Mediterranean-fed subjects. These behavioral changes were also associated with some of the effects of diet on gene expression, suggesting an interaction between diet, central nervous system activity, and monocyte gene expression. The results of this study provide new insights into evolutionary mismatch at the molecular level and uncover new pathways through which Western diets alter monocyte polarization toward a proinflammatory phenotype.

On the use of evolutionary mismatch theories in debating human prosociality

According to some evolutionary theorists human prosocial dispositions emerged in a context of inter-group competition and violence that made our psychology parochially prosocial, ie. cooperative towards in-groups and competitive towards strangers. This evolutionary hypothesis is sometimes employed in bioethical debates to argue that human nature and contemporary environments, and especially large-scale societies, are mismatched. In this article we caution against the use of mismatch theories in moral philosophy in general and discuss empirical evidence that puts into question mismatch theories based on parochial prosociality. Evolutionary mismatch theories play at best a rhetorical role in these moral debates and may misrepresent the status of relevant evolutionary research. We finally recommend that moral philosophers interested in the evolutionary literature also engage with dispositions such as xenophilia and social tolerance to counterbalance the focus on psychological mismatches adopted so far.

Copulatory Urgency: An Evolutionary Perspective of Women’s Sexual Desire

Despite the extensive empirical exploration of sexual desire, only one field explains the proper biological function of this phenomenon—evolutionary psychology. This chapter reviews women’s copulatory urgency—individual differences in the experience or intensity of sexual desire—from an evolutionary psychological perspective. An evolutionary psychological perspective of the function of sexual desire can shed light on how deficits in this motivational force may emerge, which may be useful for clinicians when helping patients understand the etiology of sexual desire concerns. An evolutionary psychological perspective of sexual desire further reveals: (1) why men and women differ in their experiences of sexual desire, (2) how natural selection produces individual differences in sexual desire, and (3) how extremes in sexual desire may be associated with hypersexuality, paraphilias, or an evolutionary mismatch between the adaptive problems faced during our species’ past and the challenges we face today. I begin the chapter by presenting a brief history of research on sexual desire and highlighting the limitations of early models of sexual responding. Next, I discuss the difficulties of measuring sexual desire, and explain how evolutionary meta-theory can be fruitful when examining context-dependent individual differences in sexual desire. I then describe the impact of several important contextual factors (e.g., age, relationship length, parental effort, partner habituation) on variation in women’s sexual desire responses and highlight avenues for future research. The chapter ends by discussing the qualities of compulsive sexual behavior and proposing that extreme variations in sexual desire as we currently understand them may be the result of an evolutionary mismatch. In sum, I suggest that scientists distinguish between sexual desire and sexual arousal, consider evolutionary meta-theory when thinking about context-dependent variation in sexual desire, and be cognizant of potential confounds when examining women’s sexual desire responses.

Prevalence and factors related to psychological distress among ethnic minority adults in a semi-modern village in rural vietnam: an evolutionary mismatch framework

ABSTRACT Background and objectives Psychological distress is one of the greatest health threats facing humanity and has been hypothesized to represent an evolutionary mismatch. This hypothesis can be tested in semi-traditional societies that are undergoing transitions to modern lifestyles. This study used an evolutionary medicine framework to examine the predictors of psychological distress symptomology in a semi-modern ethnic minority village in rural Vietnam that is transitioning into a developing economy. Methodology A cross-sectional survey was conducted in Chieng Sai Village among White Thai ethnic minority adults aged 18-75. The DASS-21 scale was used to measure the prevalence of psychological distress symptoms, and a closed format questionnaire was used to collect data on independent variables. Binary logistic regression analyses were used to determine associated factors of psychological distress symptomology. Results The prevalence of psychological distress symptoms was 22% (depression = 16.9%, stress = 16.3%). Common features of modernity, such as low levels of exercise, boredom, and low income, showed a positive association with psychological distress, while lifestyle features that were more similar to those expected in the evolutionary past and that fulfilled evolutionary adaptations, such as getting enough sleep, physical exertion, and earning sufficient income (access to resources), showed a negative association with psychological distress. Conclusions and Implications This study suggests that modern lifestyles might have generated evolutionary mismatches that are negatively impacting mental health in Chieng Sai Village. Future research should focus on determining the causal relationship between psychological distress and evolutionary mismatches. Evolutionary medicine approaches to understanding and treating psychological distress are potential forces of disease reduction to be considered in public health and educational policy. Lay Summary Approximately 22% of White Thai ethnic minority adults in the village of Cheing Sai reported psychological distress symptoms. I found that lifestyle factors unique to modern society had positive associations with psychological distress symptomology, while lifestyle factors that mimic aspects of human evolutionary past, such as exercise, had negative associations with psychological distress symptoms.

The Privacy Mismatch: Evolved Intuitions in a Digital World

Although people report grave concern over their data privacy, they take little care to protect it. We suggest that this privacy paradox can be understood in part as the consequence of an evolutionary mismatch: Privacy intuitions evolved in an environment that was radically different from the one found online. This evolved privacy psychology leaves people disconnected from the consequence of online privacy threats.