Publikationsliste KOPS

Humans vary substantially in their willingness to take risks. In a combined sample of over 1 million individuals, we conducted genome-wide association studies (GWAS) of general risk tolerance, adventurousness, and risky behaviors in the driving, drinking, smoking, and sexual domains. Across all GWAS, we identified hundreds of associated loci, including 99 loci associated with general risk tolerance. We report evidence of substantial shared genetic influences across risk tolerance and the risky behaviors: 46 of the 99 general risk tolerance loci contain a lead SNP for at least one of our other GWAS, and general risk tolerance is genetically correlated ([Formula: see text]  ~ 0.25 to 0.50) with a range of risky behaviors. Bioinformatics analyses imply that genes near SNPs associated with general risk tolerance are highly expressed in brain tissues and point to a role for glutamatergic and GABAergic neurotransmission. We found no evidence of enrichment for genes previously hypothesized to relate to risk tolerance.

This article focusses on the evolution of the school governance model in Spain since the 1980s. In Spain and elsewhere in Europe, the state’s monopoly over education has softened and new forms of educational governance have emerged. This has resulted in the decentralization of decision-making authority to individual schools, municipalities, and regions and a significant increase in school autonomy. We explore from a political science perspective how partisan preferences and teachers unions have decisively shaped the reform trajectory. We show that leftist and center-right governments and different teachers’ unions have promoted different versions of school autonomy in line with their ideological rationales, resulting in a reconfiguration of the school governance model with each change in government.

Discrimination is long seen as a meaningful factor for ethnic inequalities on rental housing markets. Yet empirically, the extent of discrimination is still debatable. For the first time, this article provides a quantitative meta-analysis of field experiments (in person audits and correspondence tests) that were run over the last four decades in the United States, Canada and Europe (N = 71). Special focus is given to a possible inflation of effect sizes by publication bias; to time trends; and to evidence for statistical discrimination. Taken together, nearly all experiments document the occurrence of ethnic discrimination. Effect sizes are inflated by publication bias, but there is still substantial evidence left once the bias is removed. The analysis reveals a consistent decline in the extent of discrimination over time, from moderate levels of discrimination in the 1970s and 1980s, up to only small but still statistically significant levels in the 1990s and 2000s. A significant part of the discriminatory behaviour can be attributed to missing information about the social status of applicants, which supports theories on statistical discrimination. It is discussed how future research could move our knowledge on the underlying mechanisms forward.

The public debate around climate change is increasingly polarized. At the same time, the scientific consensus about the causes and consequences of climate change is strong. This inconsistency poses challenges for mitigation and adaptation efforts. The translation of uncertain numerical climate projections into simpler but ambiguous verbal frames may contribute to this polarization. In two experimental studies, we investigated 1) how “communicators” verbally frame a confidence interval regarding projected change in winter precipitation due to climate change (N = 512) and 2) how “listeners” interpret these verbal frames (N = 385). Both studies were preregistered at the Open Science Framework. Communicators who perceived the change as more severe chose a concerned rather than an unconcerned verbal frame. Furthermore, communicators’ verbal frames were associated with their more general beliefs, like political affiliation and environmental values. Listeners exposed to the concerned frame perceived climate change–induced precipitation change to be more severe than those receiving the unconcerned frame. These results are in line with two pilot studies (N = 298 and N = 393, respectively). Underlying general beliefs about climate and the environment likely shape public communication about climate in subtle ways, and thus verbal framing by the media, policymakers, and peers may contribute to public polarization on climate change.

Acute stress is known to increase prosocial behavior in men via a “tend-and-befriend” pattern originally proposed as a specifically female stress response alongside the fight-or-flight response. However, the direct effects of acute stress on women’s social behavior have not been investigated. Applying the Trier Social Stress Test for groups (TSST-G), 94 women were confronted with either a stress or control condition. We repeatedly measured their subjective stress responses, salivary cortisol, and heart rate, and investigated their level of trust, trustworthiness, sharing, punishment and non-social risk using social decision paradigms. We detected significant increases in all stress parameters, as well as the wish for closeness during the stress condition. Acute stress exposure elevated prosocial trustworthiness and sharing without affecting non-social risk behavior. These results are in line with findings on the effects of stress in men, and further validate the tend-and-befriend pattern as one possible behavioral response during stress in humans.

Bilingual children are a heterogeneous population, as the amount of input and use of their languages may differ due to various factors, for example, the status of each language (majority, minority), which language is used in the school, and whether children are acquiring literacy in one or both languages. Their language ability depends to a large extent on the use of each language and on whether they each language at the same rate. The aim of the study was to investigate how primary school bilingual children in the UK perform on several domains of language and reading skills and how these relate to language dominance. Moreover, it addressed how this performance is affected by a range of contextual factors and whether there are cross-language relationships in the children’s language and reading abilities. Forty Greek-English bilingual children in Year 1 and Year 3 were tested on vocabulary, phonological awareness, morphological awareness, morpho-syntax, and decoding in Greek and English. The results showed that as a group, the children were Greek dominant before the age of 4 but English dominant now and confirm that language dominance could change even before children enter school and affects language and literacy skills equally. A strong relationship between language use and performance was only in evidence in the minority language, which suggests that parental effort should be directed towards the minority language because schooling appears to level out differences in the majority language. There was no negative relationship between the use of the heritage language and children’s language and reading performance in the majority language. In contrast, significant positive cross-language associations were revealed among vocabulary, phonological awareness, inflectional morphology and decoding skills. The practical implications of this study are that parents and teachers should be informed for the positive effects of heritage language use in and outside the home for the maintenance of the heritage language and for the development of the children’s language and literacy skills.

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The growing multitude of sophisticated event-level data collection enables novel analyses of conflict. Even when multiple event data sets are available, researchers tend to rely on only one. We instead advocate integrating information from multiple event data sets. The advantages include facilitating analysis of relationships between different types of conflict, providing more comprehensive empirical measurement, and evaluating the relative coverage and quality of data sets. Existing integration efforts have been performed manually, with significant limitations. Therefore, we introduce Matching Event Data by Location, Time and Type (MELTT)—an automated, transparent, reproducible methodology for integrating event data sets. For the cases of Nigeria 2011, South Sudan 2015, and Libya 2014, we show that using MELTT to integrate data from four leading conflict event data sets (Uppsala Conflict Data Project–Georeferenced Event Data, Armed Conflict Location and Event Data, Social Conflict Analysis Database, and Global Terrorism Database) provides a more complete picture of conflict. We also apply multiple systems estimation to show that each of these data sets has substantial missingness in coverage.

In the context of large-scale migration within and into Europe, the question of whether and under which conditions immigrants should be granted access to social benefits in the country of destination is of high political relevance. A large body of research has studied natives’ attitudes towards giving immigrants access to the welfare state, while research on attitudes of immigrants themselves is scarce. Focusing on the impact of self-interest, we compare immigrants and native citizens in their attitudes towards granting immigrants access to the welfare state. We identify three mechanisms through which self-interest can influence these attitudes: immigrant origin, socio-economic status and – for first-generation immigrants only – incorporation into the host society. We test our expectations using cross-national data from the European Social Survey round 2008. The findings suggest that self-interest is indeed one of the factors that motivate attitudes towards welfare state restrictiveness among natives and immigrants, but also point at relevant exceptions to this pattern.

While the political nature of evaluation is widely recognized, few attempts exist to conceptualize and compare these politics. This article develops the concept of evaluation stakeholder influence potential, which builds on four political resources for influence (agenda-setting powers, staff and budgetary resources, access to evaluation results, and access to evaluators). These resources are measured for both member states and international public administrations in 24 United Nations organizations. We find that the administration—and not member states—have the largest influence potential in almost two-thirds of the international organizations. Our findings allow classifying them into three groups for which we expect differences in political contestation about evaluation use: two extreme-case groups (either member state or administrative dominance) and a group of contested middle cases. This finding of bureaucratic dominance reinforces literature on bureaucrats as powerful evaluation stakeholders in domestic settings and speaks to nascent research on bureaucratic influence in international organizations.