Partner choice and cooperation in social dilemmas can increase resource inequality

Cooperation is more likely when individuals can choose their interaction partner. However, partner choice may be detrimental in unequal societies, in which individuals differ in available resources and productivity, and thus in their attractiveness as interaction partners. Here we experimentally examine this conjecture in a repeated public goods game. Individuals (n = 336), participating in groups of eight participants, are assigned a high or low endowment and a high or low productivity factor (the value that their cooperation generates), creating four unique participant types. On each round, individuals are either assigned a partner (assigned partner condition) or paired based on their self-indicated preference for a partner type (partner choice condition). Results show that under partner choice, individuals who were assigned a high endowment and high productivity almost exclusively interact with each other, forcing other individuals into less valuable pairs. Consequently, pre-existing resource differences between individuals increase. These findings show how partner choice in social dilemmas can amplify resource inequality

Freezing in response to social threat: a replication

Freezing is an adaptive defensive response to a stressful event. Recent research suggests that freezing not only occurs in response to physical threats but also in response to social threats (e.g., angry faces; Roelofs et al. in Psychol Sci 21:1575–1581, 2010). Given the practical and theoretical importance of this finding, the current study aimed to replicate and extend it. Following the original study, we measured heart rate while participants viewed emotional faces (angry, happy, neutral). Extending the original study, we included a baseline measure and performed additional, more fine-grained analyses. Our results support the hypothesis that participants show physiological signs of freezing when looking at angry faces. Importantly, we also find this effect when comparing heart rate in the angry block to baseline levels. Interestingly, the heart rate effects are explained by deceleration in the first 30 s of the 1-min angry block, but not in the second 30 s. Like Roelofs et al., we find evidence that the effects are modulated by state anxiety, but our effects are only marginal and we do not replicate the negative correlation between heart rate and state anxiety in the angry block. In general, we thus find evidence for physiological signs of freezing in response to social threat. We discuss implications and venues for future research.Social decision makin

The prospective associations between financial scarcity and financial avoidance

The current study investigated the prospective associations between financial scarcity and financial avoidance. We hypothesized that over time, financial scarcity––the experience of lacking needed financial resources––is associated with an increase in financial avoidance––the tendency to avoid dealing with one’s finances––, and vice versa. In a longitudinal panel study, including a large and representative adult sample of Dutch citizens (initial N = 1,122, final N = 837), we measured financial scarcity and financial avoidance twice over a period of 22 months. Data were analyzed using a cross-lagged panel model, which allows to test for prospective effects of one variable on the other, while controlling for autoregressive effects. Confirming our preregistered hypotheses, results showed that financial scarcity was positively related with an increase in subsequent financial avoidance, whereas financial avoidance was positively related with an increase in subsequent financial scarcity. While these longitudinal findings are not causal, they are in line with the concept of a poverty trap, where financial scarcity and financial avoidance form a temporally dynamic and increasing relationship.Social decision makin

Financial scarcity increases discounting of gains and losses: experimental evidence from a household task

People experience financial scarcity when they have insufficient financial resources to meet demands, and this experience can affect decision-making in various ways. One proposed consequence of financial scarcity is increased temporal discounting, which is a tendency to value immediate outcomes more strongly than delayed outcomes. To test whether financial scarcity indeed increases temporal discounting, we developed the Household Task—an experimental paradigm during which participants have to manage the finances of a household. In a pilot, we found that manipulating participants’ financial situation in the Household Task (debts vs. savings and control) induced an experience of financial scarcity. Next, Experiments 1 and 2 confirmed that this experience increased temporal discounting of gains and losses. In Experiments 3 and 4, we tested whether experienced scarcity also increases discounting when financial resources were equal between conditions. However, in these experiments, there was no evidence of such an effect. In Experiment 5, we found that discounting increased when available financial resources were constant while expectations about future financial problems might have differed between conditions. In sum, the current research suggests that when experiencing scarcity, discounting increases as a response to a current or anticipated future shortcoming of available financial resources. Yet, there was no evidence suggesting that discounting increases when a scarcity mindset is induced in isolation.Social decision makin

StatBreak: identifying "lucky" data points through genetic algorithms

Sometimes interesting statistical findings are produced by a small number of “lucky” data points within the tested sample. To address this issue, researchers and reviewers are encouraged to investigate outliers and influential data points. Here, we present StatBreak, an easy-to-apply method, based on a genetic algorithm, that identifies the observations that most strongly contributed to a finding (e.g., effect size, model fit, p value, Bayes factor). Within a given sample, StatBreak searches for the largest subsample in which a previously observed pattern is not present or is reduced below a specifiable threshold. Thus, it answers the following question: “Which (and how few) ‘lucky’ cases would need to be excluded from the sample for the data-based conclusion to change?” StatBreak consists of a simple R function and flags the luckiest data points for any form of statistical analysis. Here, we demonstrate the effectiveness of the method with simulated and real data across a range of study designs and analyses. Additionally, we describe StatBreak’s R function and explain how researchers and reviewers can apply the method to the data they are working with.Social decision makin

Conformal and Affine Hamiltonian Dynamics of General Relativity

The Hamiltonian approach to the General Relativity is formulated as a joint nonlinear realization of conformal and affine symmetries by means of the Dirac scalar dilaton and the Maurer-Cartan forms. The dominance of the Casimir vacuum energy of physical fields provides a good description of the type Ia supernova luminosity distance--redshift relation. Introducing the uncertainty principle at the Planck's epoch within our model, we obtain the hierarchy of the Universe energy scales, which is supported by the observational data. We found that the invariance of the Maurer-Cartan forms with respect to the general coordinate transformation yields a single-component strong gravitational waves. The Hamiltonian dynamics of the model describes the effect of an intensive vacuum creation of gravitons and the minimal coupling scalar (Higgs) bosons in the Early Universe.Comment: 37 pages, version submitted to Gen. Rel. Gra

Astronomical Distance Determination in the Space Age: Secondary Distance Indicators

The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)