Innumeracy, that is, the inability to deal with numbers and provide correct estimates about political issues, is reported to be widespread among the public. Yet, despite the recognition that a conspiracy mindset is an increasingly common phenomenon in Western democracies, this has not been considered as a potential correlate of innumeracy. Using data from an online sample of respondents across 10 European countries, we show that those with a higher propensity to hold a conspiracy worldview tend to overestimate the actual share of the immigrant population living in their own country. This association holds true when accounting for country heterogeneity and other cognitive, affective and socio-demographic factors. Employing a comparative design and refined measurements, the article contributes to our understanding of how a conspiracy mentality may influence perceptions of relevant political facts, questioning basic processes of democratic accountability.

The article offers an overview of the use of survey experiments in political research by relying on available examples, bibliographic data and a content analysis of experimental manuscripts published in leading academic journals over the last two decades. After a short primer to the experimental approach, we discuss the development, applications and potential problems to internal and external validity in survey experimentation. The article also provides original examples, contrasting a traditional factorial and a more innovative conjoint design, to show how survey experiments can be used to test theory on relevant political topics. The main challenges and possibilities encountered in envisaging, planning and implementing survey experiments are examined. The article outlines the merits, limits and implications of the use of the experimental method in political research.

Genetic structure may be highly variable across seabird species, and particularly among those that are distributed over large geographical areas. The Adélie penguin (Pygoscelis adeliae) is a numerically dominant Antarctic seabird that is considered to be a key species in coastal ecosystems. Since the Last Glacial Maximum, penguin colonization of the Antarctic coastline occurred at varying geographical and temporal scales, contributing to an incomplete understanding of how modern colonies relate to each other at local or regional scales. We assessed the population genetic structure of Adélie penguins (n = 86 individuals) from three adjacent colonies along the Victoria Land coast using molecular genetic markers (i.e. seven microsatellite loci isolated through next-generation sequencing). Our results indicate meta-population dynamics and possibly relationships with habitat quality. A generally low genetic diversity (Nei's index: 0.322–0.667) was observed within each colony, in contrast to significant genetic heterogeneity among colonies (pairwise FST = 0.071–0.148), indicating that populations were genetically structured. Accordingly, an assignment test correctly placed individuals within the respective colonies from which they were sampled. The presence of inter-colony genetic differentiation contrasts with previous studies on this species that showed a lack of genetic structure, possibly due to higher juvenile or adult dispersal. Our sampled colonies were not panmictic and suggest a lower migration rate, which may reflect relatively stable environmental conditions in the Ross Sea compared to other regions of Antarctica, where the ocean climate is warming.

The ecological drivers underlying breeding performance are expected to differ across the geographical range of seabird species, but few studies have compared trade-offs between colonies with different local conditions. During chick-rearing (2000–01), we compared the foraging trips, diet and breeding parameters of two Adélie penguin colonies in the Ross Sea, at Edmonson Point (EdPo; ~2000 breeding pairs) and Inexpressible Island (InIs; ~24 000 breeding pairs). Penguins from InIs travelled farther and performed longer feeding trips. The quantity of food brought to the nest was the same for the two colonies, but penguins from InIs brought more fish and less krill. Eggs hatched earlier at EdPo. Breeding success did not differ, but chick weight during hatching–fledging was greater at InIs. Despite worse weather conditions at InIs, the larger proportion of high-energy food brought by penguins from InIs (i.e. fish) may explain their offspring‘s better performance. In addition, the persistence of fast ice at EdPo may have led to greater energy expenditure of breeding individuals, possibly reducing chick growth. The greater intraspecific competition expected at InIs may have been reduced by longer foraging trips and/or counteracted by the more nutritious diet. Our findings reveal complex trade-offs between foraging effort and environmental constraints in determining the breeding performance of Adélie penguins.

The article compares the way Italian (governmental and political) elites and (organized and general) publics perceive the international system and conceive of the role of Italy in it by using an ad hoc survey conducted specifically for this study. In order to establish whether a horizontal (left-right) and vertical (top-down) consensus exists on foreign policy, special attention has been paid to divergence and convergence patterns in terms of threat perception, feelings towards the (American and European) allies, support for the main institutional mechanisms of coordination and cooperation, and willingness to use military power to defend the constituted order and the national interest, while controlling for the position and level of action of each actor within the foreign policy-making process as well as her or his ideological orientation. While tracing elites’ and publics’ attitudes towards a wide range of foreign policy and security issues, the article reveals the effect of ideological and situational factors on the strategic preferences of national policy-makers and public opinion. In doing this, it contributes to define both the substance and boundaries of the alleged consensus, based on shared norms and historical legacies, supposedly overcoming socio-economic and political cleavages in matters of foreign policy.