Changes in Behaviour and Body Weight Following a Single or Double Social Defeat in Rats

In a series of experiments, the consequences of a single and double social conflict on various behaviours and body weight in rats were studied. Animals were subjected to social defeat by placing them into the territory of an aggressive male conspecific for one hour, either once, or twice at the same time on two consecutive days. To assess the consequences of social defeat, three experiments were performed with independent groups of rats. In the first experiment, an open field test was performed two days after the last conflict. Locomotor activity was strongly reduced after social defeat. There were no differences between the single and double defeat group. To assess the effects of social defeat on subsequent social behaviour, a second experiment was performed in which experimental animals were confronted with an unfamiliar non-aggressive rat two days after a single or double conflict. Social defeat resulted in a reduction of social contact with the unfamiliar conspecific. There was no difference between the single and double conflict group. In the third experiment, the effects of social conflict on food intake, body weight and saccharine preference were measured. Food intake was not affected after a single conflict, but in the double conflict group food intake was decreased for several days. Body weight gain was decreased after both single and double social defeat. The decrease was stronger in the double conflict group. Water intake and saccharine preference were not significantly affected. This study revealed that social defeat in rats causes pronounced changes in various behaviours and body weight. Different aspects of behaviour are differentially affected by defeat with respect to the magnitude and time course of the changes induced. Moreover, different behavioural parameters are differentially sensitive to repetition of the stressor.     

Are cognitive differences between immigrant and majority groups diminishing?

A review is given of scores on various cognitive measures, comparing groups of ethnic Dutch and non‐Western immigrants using a large number of datasets. The research shows that there are large group differences in school results, work proficiency, and g for Turks, Moroccans, Surinamese, Netherlands Antilleans, and Indonesians from the Moluccans compared with ethnic Dutch. However, South‐East Asians score higher, and persons with one immigrant and one ethnic Dutch parent score only slightly below the mean of the Dutch. When comparing first‐generation disadvantaged immigrant groups with later generations the data show substantial improvements for g, a remarkable stability of educational differences for younger children, and a clear improvement in educational achievement at the end of primary school. Indirect data on intergenerational improvements in work proficiency appear suggestive of a trend of closing gaps. Some of the data reflect higher cognitive capacities over time, and this enhances integration of immigrants into Dutch society. Causes of group differences and improvements in mean level of g are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

Knowledge about the distribution of information and group decision making: When and why does it work?

Research has shown that decision-making groups with distributed information perform better when group members know which member is knowledgeable about what. Thus far research has been unable to identify the process responsible for this effect. In the present study, we propose that group members’ task representations mediate the effect of knowledge about the distribution of information on decision performance. Building on this proposition, we also propose that reflection about the task moderates the effect of knowledge about distributed information through its effect on task representations. These hypotheses were put to the test in an experimental study of decision-making groups (N = 125). As predicted, knowledge of distributed information interacted with reflection to affect decision quality. Findings confirmed the proposed mediating role of task representations and information elaboration.     

An Ethical Argument in Favor of Nano-enabled Diagnostics in Livestock Disease Control

Livestock production has been confronted with several epidemics over the last decades. The morality of common animal disease strategies—stamping out and vaccination—is being debated and provokes controversies among farmers, authorities and the broader public. Given the complexity and controversy of choosing an appropriate control strategy, this article explores the potential of nano-enabled diagnostics in future livestock production. At first glance, these applications offer promising opportunities for better animal disease surveillance. By significantly shortening the reaction time from diagnosis to appropriate control, they could complement the current disease management strategies. Although nano-enabled diagnostics will not make livestock disease eradication strategies redundant or completely free of the culling of infected animals, these diagnostics could significantly reduce the number of culled animals and animal suffering. This article aims to demonstrate that the ethical assessment of advanced diagnostics can build on the experiences with decision making in biomedical ethics where nonmaleficence, beneficence, autonomy and justice serve as important benchmarks. Nano-enabled diagnostics may be an ethically sound solution if it can resolve the dilemma between stamping out and vaccination in favor of the latter and if it can balance the autonomy–paternalism dilemma between farmers and authorities. The technology should allow to be switched on and off by farmers, whilst simultaneously allowing for a weak paternalism on behalf of authorities in order to benefit the farmer and broader society and to protect them from harm.

If we have the will,there will be a way: regulatory focus as a group identity

Based on social identity theory and regulatory focus theory, we predicted that promotion and prevention strategies can be part of the identity of a group (i.e., collective regulatory focus) which in turn influences the behavior and experienced emotions of individual group members. We conducted two experiments to test this prediction. After assessing participants' personal regulatory focus preference, collective regulatory focus was induced by showing participants group mottos, allegedly chosen by other members of their group, that either voiced a promotion or a prevention strategy preference. Both experiments yielded evidence for our prediction in that the collective regulatory focus shifted the behavior of individual group members on a signal detection task towards promotion‐ (liberal bias) or prevention‐ (conservative bias) consistent behavior and influenced the emotions they experienced. Experiment 2 further substantiated our group identity rationale by showing that these effects were especially strong for high identifiers. Copyright © 2007 John Wiley & Sons, Ltd.     

Suffering from the possibility of status loss: Physiological responses to social identity threat in high status groups

In this research, we examine the emergence of social identity threat among members of high status groups, by assessing physiological responses to threat in addition to more traditional (self‐report) measures. We argue that physiological measures are better suited than explicit responses to indicate the emergence of social identity threat when high status groups face the possibility of future group status loss. In Experiment 1, members of an experimentally created high status group displayed higher systolic blood pressure (SBP) and pulse pressure (PP) when inter‐group status differences were unstable than when they were stable, even though participants in both conditions reported identical levels of collective self‐esteem. In Experiment 2, only male participants (i.e., high status group members) displayed increased SBP and PP when discussing changing gender–status relations in society, particularly when this happened in an inter‐group context (i.e., when discussing with females). The increased threat that emerged under these conditions could not be inferred from self‐reported inter‐group perceptions (endorsement of sexism). We conclude that whereas self‐report measures can help assess how high status group members perceive the current inter‐group situation, physiological measures are needed to reveal the social identity threat they experience when they anticipate the possibility for future change in inter‐group relations. Copyright © 2009 John Wiley & Sons, Ltd.     

Moral Contextualism and the Problem of Triviality

Moral contextualism is the view that claims like ‘A ought to X’ are implicitly relative to some (contextually variable) standard. This leads to a problem: what are fundamental moral claims like ‘You ought to maximize happiness’ relative to? If this claim is relative to a utilitarian standard, then its truth conditions are trivial: ‘Relative to utilitarianism, you ought to maximize happiness’. But it certainly doesn’t seem trivial that you ought to maximize happiness (utilitarianism is a highly controversial position). Some people believe this problem is a reason to prefer a realist or error theoretic semantics of morals. I argue two things: first, that plausible versions of all these theories are afflicted by the problem equally, and second, that any solution available to the realist and error theorist is also available to the contextualist. So the problem of triviality does not favour noncontextualist views of moral language.     

Continuing and changing group identities: the effects of merging on social identification and ingroup bias

A social identity approach to the investigation of group-based reactions to a merger is outlined, in which a merger is analyzed in terms of the continuation or change of the pre-merger group identity. In two experiments, the relationship between pre-merger identification, post-merger identification, and ingroup bias was investigated using a minimal group paradigm. Results from both studies showed that the perceived continuation of the pre-merger group identity in the post-merger group strengthened the positive relationship between pre-merger identification and identification with the superordinate post-merger group. Moreover, perceived continuation strengthened, rather than reduced, ingroup bias at the subordinate level of the merged groups. Some theoretical and practical implications are discussed.     

Anger and social appraisal: a "spicy" sex difference?

The central objective of this study was to investigate the role of social appraisal in sex differences in anger expression. Anger expression was inferred from the amount of hot sauce given to the person who induced anger. Participants were randomly assigned to a social condition, in which they expected to meet this person, or to a nonsocial condition, in which they had no such expectation. Men and women differed in their anger expressions, despite the fact that they did not differ in anger experience. Women expressed anger to a lesser extent than men, but only in the social condition. Social appraisal partly mediated the relation between sex and anger expression. The role of social appraisal in emotion and appraisal theory is discussed.