Vector-based model of elastic bonds for DEM simulation of solids

A new model for computer simulation of solids, composed of bonded rigid body particles, is proposed. Vectors rigidly connected with particles are used for description of deformation of a single bond. The expression for potential energy of the bond and corresponding expressions for forces and moments are proposed. Formulas, connecting parameters of the model with longitudinal, shear, bending and torsional stiffnesses of the bond, are derived. It is shown that the model allows to describe any values of the bond stiffnesses exactly. Two different calibration procedures depending on bond length/thickness ratio are proposed. It is shown that parameters of model can be chosen so that under small deformations the bond is equivalent to either Bernoulli-Euler rod or Timoshenko rod or short cylinder connecting particles. Simple expressions, connecting parameters of V-model with geometrical and mechanical characteristics of the bond, are derived. Computer simulation of dynamical buckling of the straight discrete rod and half-spherical shell is carried out.Comment: 11 pages, 6 figure

Measuring the closeness of relationships: a comprehensive evaluation of the 'Inclusion of the Other in the Self' scale

Understanding the nature and influence of social relationships is of increasing interest to behavioral economists, and behavioral scientists more generally. In turn, this creates a need for tractable, and reliable, tools for measuring fundamental aspects of social relationships. We provide a comprehensive evaluation of the 'Inclusion of the Other in the Self' (IOS) Scale, a handy pictorial tool for measuring the subjectively perceived closeness of a relationship. The tool is highly portable, very easy for subjects to understand and takes less than 1 minute to administer. Across our three online studies with a diverse adult population (n=772) we show that six different scales designed to measure relationship closeness are all highly significantly positively correlated with the IOS Scale. We then conduct a Principal Component Analysis to construct an Index of Relationship Closeness and find that it correlates very strongly (ρ=.85) with the IOS Scale. We conclude that the IOS Scale is a psychologically meaningful and highly reliable measure of the subjective closeness of relationships

The role of collective narcissism in populist attitudes and the collapse of democracy in Hungary

What are the psychological processes responsible for the recent spread of populist political systems and movements? All political systems essentially reflect the mental representations of their populations, and collective narcissism has recently emerged as a contributing factor in the rise of populism. This article presents two studies examining the role of collective narcissism in predicting populist attitudes and voting intentions in Hungary. Hungary offers a particularly important case study of state-sponsored populism and illiberalism in Europe, as this country has gone furthest in undermining democratic principles and practices within the EU. To establish the pervasive role of collective narcissism we first review the historical evidence, survey research, and narrative analyses of Hungarian political representations. We then present two empirical studies where we predicted and found that collective narcissism was a significant predictor of negative attitudes toward the EU (Study 1), conservatism, and support for the ruling populist party (Studies 1 and 2). Collective narcissism predicted these variables independently from other factors, such as in-group positivity or perceived relative deprivation. However, once conservatism was controlled for the effects of collective narcissism faded out in some cases. The results nevertheless indicate that collective narcissism plays important role in promoting populist politics. The implications of these findings for understanding the psychological appeal of populism and illiberalism are discussed

Using social and behavioural science to support COVID-19 pandemic response

The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behavior with the recommendations of epidemiologists and public health experts. Here we discuss evidence from a selection of research topics relevant to pandemics, including work on navigating threats, social and cultural influences on behaviour, science communication, moral decision-making, leadership, and stress and coping. In each section, we note the nature and quality of prior research, including uncertainty and unsettled issues. We identify several insights for effective response to the COVID-19 pandemic, and also highlight important gaps researchers should move quickly to fill in the coming weeks and months

Increasing altruistic and cooperative behaviour with simple moral nudges

The conflict between pro-self and pro-social behaviour is at the core of many key problems of our time, as, for example, the reduction of air pollution and the redistribution of scarce resources. For the well-being of our societies, it is thus crucial to find mechanisms to promote pro-social choices over egoistic ones. Particularly important, because cheap and easy to implement, are those mechanisms that can change people's behaviour without forbidding any options or significantly changing their economic incentives, the so-called "nudges". Previous research has found that moral nudges (e.g., making norms salient) can promote pro-social behaviour. However, little is known about whether their effect persists over time and spills across context. This question is key in light of research showing that pro-social actions are often followed by selfish actions, thus suggesting that some moral manipulations may backfire. Here we present a class of simple moral nudges that have a great positive impact on pro-sociality. In Studies 1-4 (total N = 1,400), we use economic games to demonstrate that asking subjects to self-report "what they think is the morally right thing to do" does not only increase pro-sociality in the choice immediately after, but also in subsequent choices, and even when the social context changes. In Study 5, we explore whether moral nudges promote charity donations to humanitarian organisations in a large (N = 1,800) crowdfunding campaign. We find that, in this context, moral nudges increase donations by about 44 percent

Donor misreporting:conceptualizing social desirability bias in giving surveys

Although survey research is one of the most frequently used methods for studying charitable giving, the quality of the data is seldom stated or known. In particular, social desirability bias (SDB) has been found to distort data validity where respondents tend to over-report what is socially desirable and vice versa. We argue that this phenomenon has not been fully understood in the nonprofit context as existing social desirability scales are not appropriate to be used in giving surveys. Thus, this paper is the first to extend understanding of SDB to the nonprofit context and to explore its motivating factors. Based on a multidisciplinary literature review and qualitative interviews with various senior practitioners from the fundraising and marketing research sectors, it is suggested that SDB is a multidimensional construct yielding five dimensions, namely, impression management, self-deception, level of involvement, perceived benefits and social norms. The paper then discusses the implications for nonprofit researchers and concludes with directions for future research