We gratefully acknowledge all the participants that took part in these three studies. We are particularly grateful to a number of undergraduate and MSc students that acted as research assistants and contributed to data collection at London Metropolitan University and Queen's University Belfast. The studies were not preregistered. Author Contributions K.A.P. has written the manuscript and he was responsible for data collection and data preparation; F.M.G., D.B., P.W. and G.B.M. were responsible for data collection and data preparation for study 3; K.A.P., F.M.G. and G.B.M. have performed the statistical analyses; P.J.C. and G.B.M. provided critical reviews and comments during the write-up of this manuscript. P.J.C. is responsible for the conceptualisation of MT (as described in this manuscript) and the creation of the MTQ48 to assess MT; K.A.P. was responsible for the overall conceptualisation of the studies that are presented in this manuscript. All authors contributed to the revisions of this manuscript.

Objective:We employed the network methodology to explore the connections be tween the Dark Triad (DT) traits with Mental Toughness (MT) and the degree to which they account for perceived stress beyond the Big Five (B5). Method: Network analyses were undertaken to explore connections between the DT, MT, and perceived stress, independently in two samples, and in the combined data set; and whether B5 factors are responsible for the connections that emerged in the original network. Results: DT and MT traits improved the prediction of perceived stress above the B5.Furthermore, narcissism occupied a strategic position in the network acting as a bridge between prosocial and "dark" sides of personality. The pattern of network connections could not be explained by B5 traits alone. Conclusions:The results suggest that there is more to personality than what can be captured by the B5 and that broadening the domain of personality beyond the B5 can improve the prediction of important outcomes, such as perceived stress. Narcissism is a unique trait and studying its connection with MT may be the key to moving for ward from a dichotomous way of perceiving personality traits, as beneficial or ma levolent, to focusing on a dynamic continuum of personality.

Despite being bio-epidemiological phenomena, the causes and effects of pandemics are culturally influenced in ways that go beyond national boundaries. However, they are often studied in isolated pockets, and this fact makes it difficult to parse the unique influence of specific cultural psychologies. To help fill in this gap, the present study applies existing cultural theories via linear mixed modeling to test the influence of unique cultural factors in a multi-national sample (that moves beyond Western nations) on the effects of age, biological sex, and political beliefs on pandemic outcomes that include adverse financial impacts, adverse resource impacts, adverse psychological impacts, and the health impacts of COVID. Our study spanned 19 nations (participant N = 14,133) and involved translations into 9 languages. Linear mixed models revealed similarities across cultures, with both young persons and women reporting worse outcomes from COVID across the multi-national sample. However, these effects were generally qualified by culture-specific variance, and overall more evidence emerged for effects unique to each culture than effects similar across cultures. Follow-up analyses suggested this cultural variability was consistent with models of pre-existing inequalities and socioecological stressors exacerbating the effects of the pandemic. Collectively, this evidence highlights the importance of developing culturally flexible models for understanding the cross-cultural nature of pandemic psychology beyond typical WEIRD approaches.

Research has shown that levels of the Dark Triad (i.e., traits of Machiavellianism, narcissism, and psychopathy) vary across sex and age, with males and younger people reporting higher scores. The Dark Triad has also been found to be associated with personal economic status. We investigated whether sex and age differences in the Dark Triad varied across countries of different socioeconomic conditions. We further explored whether the dark traits predicted personal income to different extent across countries. We utilized three samples from the UK, Greece, and China (total N = 5,854), whose socioeconomic status varied from more to less developed according to the Human Development Index. Men scored higher than women on the Dark Triad, with the magnitude of sex differences being largest in the UK, followed by Greece and China. Younger people scored higher than older people on the Dark Triad, with the effect of age varying across countries. Narcissism positively predicted income, with its predictive power being significant in China and Greece but null in the UK. The results are consistent with the view that Dark Triad traits may be adaptive responses to environmental challenges. Specifically, the results suggest that sex differences in the Dark Triad and the relation between narcissism and personal income are responsive to socioeconomic conditions at the country level.

At the onset of the novel coronavirus (COVID-19) pandemic, countries reported elevated rates of psychiatric symptoms. Previous research indicates that subclinical narcissism may reduce depression and stress through mental toughness. The researchers collected data from the United Kingdom (UK) and Greece (GR) on self-reported depression, anxiety, stress, COVID-19 related worry, subclinical narcissism, and mental toughness. Two samples, one cross-sectional (N = 1846) and one semi-longitudinal (N = 184), were used to compare rates of psychiatric symptoms pre and during COVID-19 across the UK and GR, and to test a path model in which subclinical narcissism reduced psychiatric symptoms through mental toughness. From pre to during COVID-19, UK participants exhibited increased depression, lower anxiety, and no change in stress, whereas GR participants showed a decrease in anxiety and stress and consistently low symptoms of depression. Subclinical narcissism exerted a negative indirect effect on psychiatric symptoms through mental toughness in both samples, but a negative total effect on anxiety and stress only in the UK sample. Findings indicate that exploring links between narcissism and prosocial traits can provide novel insights into differences in the adaptive use of personality traits in relation to mental health.