The definition of metabolic syndrome (MetS) has been, and still is, extremely controversial. My purpose is not to give a solution to the associated debate but to argue that the controversy is at least partially due to the different 'causal content' of the various definitions: their theoretical validity and practical utility can be evaluated by reconstructing or making explicit the underlying causal structure. I will therefore propose to distinguish the alternative definitions according to the kinds of causal content they carry: (1) definitions grounded on associations, (2) definitions presupposing a causal model built upon statistical associations , and (3) definitions grounded on underlying mechanisms. I suggest that analysing definitions according to their causal content can be helpful in evaluating alternative definitions of some diseases. I want to show how the controversy over MetS suggests a distinction among three kinds of definitions based on how explicitly they characterise the syndrome in causal terms, and on the type of causality involved. I will call 'type 1 definitions' those definitions that are purely associative; 'type 2 definitions' the definitions based on statistical associations, plus generic medical and causal knowledge; and 'type 3 definitions' the definitions based on (hypotheses about) mechanisms. These kinds of definitions, although different, can be related to each other. A definition with more specific causal content may be useful in the evaluation of definitions characterised by a lower degree of causal specificity. Moreover, the identification of the type of causality involved is of help to constitute a good criterion for choosing among different definitions of a pathological entity. In section (1) I introduce the controversy about MetS, in section (2) I propose some remarks about medical definitions and their 'causal im-port', and in section (3) I suggest that the different attitudes towards the definition of MetS are relevant to evaluate their explicative power.

ABSTRACT Research in the" contact hypothesis" tradition shows that some types of contacts can lead to more positive attitudes towards minorities. This paper compares the effects of friends, networks, and voluntary associations on positive attitudes towards immigrants and ethnic minorities in Canada, using the 2004 Canadian federal election survey. We assess the impact of a person's network as a whole through a gendered position generator.

Cite: Wagner, W., Kronberger, N., Nagata, M., Sen, R., Holtz, P., & Flores Palacios, F. (2010). Essentialist theory of ‘hybrids’: From animal kinds to ethnic categories and race. Asian Journal of Social Psychology, 13(4), 232-246. doi: 10.1111/j.1467-839X.2010.01315. This article presents a theory of the perception of hybrids, resulting from cross-breeding natural animals that pertain to different species and of children parented by couples with a mixed ethnic or racial background. The theory states that natural living beings, including humans, are perceived as possessing a deeply ingrained characteristic that is called 'essence' or 'blood' or 'genes' in everyday discourse and that uniquely determines their category membership. If, by whatever means, the genes or essences of two animals of different species are combined in a hybrid, the two incompatible essences collapse, leaving the hybrid in a state of non-identity and non-belonging. People despise this state and reject the hybrid (Study 1). This devaluation effect holds with cross-kind hybrids and with hybrids that arise from genetically combining animals from incompatible habitats across three cultures: Austria, India and Japan (Study 2). In the social world, groups and ethnic or racial categories frequently are essentialized in an analogue way. When people with an essentialist mindset judge ethnically or racially mixed offspring, they perceive a collapse of ethnic or racial essence and, consequently, denigrate these children, as compared to children from 'pure' in-group or out-group parents (Study 3). The findings are discussed in terms of the widespread 'yuck factor' against genetically modified animals, in terms of the cultural concepts of monstrosity and of racism and prejudice.