Bicycle helmets – A case of risk compensation?

Several studies have shown that bicycle helmets have the potential of reducing injuries from accidents. Yet, no studies have found good evidence of an injury reducing effect in countries that have introduced bicycle helmet legislation. Two of the most promising explanations for why helmet laws do not work as intended are risk compensation and shifts in the cycle population as a response to the law.The present article investigates whether the lack of effect of helmet wearing laws is due to risk compensation mechanisms or population shifts (i.e. discouraging cyclists with the lowest accident risk, and thereby increasing the overall average risk per cyclist). A random sample of 1504 bicycle owners in Norway responded to a questionnaire on among other things helmet use, bicycle equipment use, accident involvement, cycling behaviour and risk perception. Data were analysed by using structural equation model (SEM). The results show that the cyclist population in Norway can be divided into two sub-populations: one speed-happy group that cycle fast and have lots of cycle equipment including helmets, and one traditional kind of cyclist without much equipment, cycling slowly. With all the limitations that have to be placed on a cross sectional study such as this, the results indicate that at least part of the reason why helmet laws do not appear to be beneficial is that they disproportionately discourage the safest cyclists.     

Associative memory or algorithmic search: a comparative study on learning strategies of bats and shrews

Two common strategies for successful foraging are learning to associate specific sensory cues with patches of prey ("associative learning") and using set decision-making rules to systematically scan for prey ("algorithmic search"). We investigated whether an animal's life history affects which of these two foraging strategies it is likely to use. Natterer's bats (Myotis nattereri) have slow life-history traits and we predicted they would be more likely to use associative learning. Common shrews (Sorex araneus) have fast life-history traits and we predicted that they would rely more heavily on routine-based search. Apart from their marked differences in life-history traits, these two mammals are similar in body size, brain weight, habitat, and diet. We assessed foraging strategy, associative learning ability, and retention time with a four-arm maze; one arm contained a food reward and was marked with four sensory stimuli. Bats and shrews differed significantly in their foraging strategies. Most bats learned to associate the sensory stimuli with the reward and remembered this association over time. Most shrews searched the maze using consistent decision-making rules, but did not learn or remember the association. We discuss these results in terms of life-history traits and other key differences between these species. Our results suggest a link between an animal's life-history strategy and its use of associative learning.     

Facilitating and inhibiting effects of priming and selection criteria in a sequence of dichotic listening trials

Competing models of attention make different predictions of how priming from recent stimulus processing could interact with intended selection. The present experiment examined the interaction between exogenous attention and endogenous priming across trial sequences. A sound cue directed attention to left, right or both sides before a dichotic syllable pair was presented. Participants were asked to report one syllable from each trial. Results showed that responses were slower on trials where one of the presented syllables had also been presented on the previous trial. Within these trials, the repeated syllable was selected less frequently, and the responses doing so were slower. Examined according to response choice on the preceding trial, syllables that had been ignored on the preceding trial tended to be ignored on the current trial (negative priming), while syllables that had been selected on the preceding trial tended to be selected on the current trial (positive priming). Responses that followed these selection biases were faster than responses that did not. Response selection was also influenced by the attention direction cue for the current trial, but not by the cue presented on the preceding trial. The results support an attentional model where traces from the preceding processing are retained, and current selection is biased to minimize cognitive conflict between recent and current processing. Negative priming appears to be due to after-effects of preceding processing, independently of the intentions behind that processing. The study accounts for positive and negative priming of dichotic listening sequences within an established, computationally viable biased competition framework.     

Stereotype threat in salary negotiations is mediated by reservation salary

Women are stereotypically perceived as worse negotiators than men, which may make them ask for less salary than men when under stereotype threat (Kray et al., 2001). However, the mechanisms of stereotype threat are not yet properly understood. The current study investigated whether stereotype threat effects in salary negotiations can be explained by motivational factors. A total of 116 business students negotiated salary with a confederate and were either told that this was diagnostic of negotiating ability (threat manipulation) or not. Measures of minimum (reservation) and ideal (aspiration) salary goals and regulatory focus were collected. The finding (Kray et al., 2001) that women make lower salary requests than men when under stereotype threat was replicated. Women in the threat condition further reported lower aspiration salary, marginally significantly lower reservation salary and less eagerness/more vigilance than men. Reservation salary mediated the stereotype threat effect, and there was a trend for regulatory focus to mediate the effect. Thus, reservation salary partly explains why women ask for less salary than men under stereotype threat. Female negotiators may benefit from learning that stereotype threat causes sex-differences in motivation.     

A randomized controlled trial of mother–infant psychoanalytic treatment: I. Outcomes on self‐report questionnaires and external ratings

Mother–infant relationship disturbances occur in three domains: maternal distress, infant functional problems, and relationship difficulties. They constitute common clinical problems. In Sweden, they are usually handled by nurses as part of public Child Health Centre care. Severe cases are referred to child psychiatry services. This randomized controlled trial compared two groups of mother–infant dyads in a Stockholm sample. One received only Child Health Centre care (the “CHCC” group) while the other received mother–infant psychoanalytic treatment plus CHCC (the “MIP” group). Eighty dyads of mothers and infants under 1½ years of age where the mothers had serious concerns about themselves in their role as mothers, their infants' well‐being, or the mother–baby relationship were randomly selected for either the MIP or the CHCC group. The primary outcomes were mother‐reported depression, mother‐reported infant functional problems, and interviewer‐based relationship assessments, all at 6 months after joining the project. Secondary outcomes were mother‐reported stress and general psychic distress, externally rated video‐recorded interactions, and the consumption of healthcare at the CHC, again all after 6 months. Intent‐to‐treat analyses of Treatment × Time effects significantly favored MIP treatment for maternal depression, mother–infant relationships, and maternal sensitivity. Effects were nearly significant on maternal stress, but nonsignificant on mother‐reported infant functional problems, general psychic distress, maternal interactive structuring and nonintrusiveness, infant responsiveness and involvement, and healthcare consumption. MIP treatment improved mother–infant relationships and maternal sensitivity and depression, all of which are known to influence child development. If effects persist and are reproduced, MIP treatment holds promise for more widespread use.     

Criterion Validity is Maintained When Items are Evaluatively Neutralized: Evidence from a Full‐scale Five‐factor Model Inventory

The original version and an evaluatively neutralized version (with items rephrased to reduce popularity) of a personality inventory were compared. The results revealed (i) similar criterion validity across three different sets of self‐rated behaviours, (ii) stronger relations to the rated social desirability of criteria for the original version and (iii) less correlation between factors for the neutralized version. We take the results to indicate that evaluative neutralization is a viable technique for reducing social desirability in self‐ratings. Implications for test construction are discussed. Copyright © 2014 European Association of Personality Psychology     

Does Low Dose Ionizing Radiation Cause Cancer? The Interplay of Epistemology and Ethics in Radiation Protection

In order to investigate the relationship between scientific evidence and social commitments this article addresses three questions: (1) does low dose ionizing radiation cause cancer? (2) Is the answer to this question different in a social setting than in a scientific context? (3) What are the consequences of the answers of 1 and 2 for the relationship between epistemology and ethics as played out in radiation protection? Conceptual analysis with basis in the philosophy of science, in particular traditional theories of causality. Whether low dose ionizing radiation causes cancer deeply depends on what we mean by causality. According to traditional scientific conceptions of causality it is not warranted to say that low dose ionizing radiation causes cancer. Standard approaches in radiation protection, however, imply that there is a causal connection, which is due to the strong social commitment in the field. There is a close relationship between social and scientific conceptions of causality, posing a series of challenges: one being that scientists covertly become moral experts, another one that the general public can be misinformed. There is a difference between causality in science and in policy making. Mixing these conceptions, as sometimes is done in radiation protection, can be misleading. Whether low dose ionizing radiation causes cancer is a social and not only a scientific issue. As such those who are warranted to have a say.     

Over-Determined Harms and Harmless Pluralities

A popular strategy for meeting over-determination and pre-emption challenges to the comparative counterfactual conception of harm is Derek Parfit’s suggestion, more recently defended by Neil Feit, that a plurality of events harms A if and only if that plurality is the smallest plurality of events such that, if none of them had occurred, A would have been better off. This analysis of ‘harm’ rests on a simple but natural mistake about the relevant counterfactual comparison. Pluralities fulfilling these conditions make no difference to the worse for anyone in the over-determination cases that prompted the need for revising the comparative conception of harm to begin with. We may choose to call them harmful anyway, but then we must abandon the idea that making a difference to the worse for someone is essential to harming. I argue that we should hold on to the difference-making criterion and give up the plural harm principle. I offer an explanation of why Parfit’s and Feit’s plural harm approach seems attractive. Finally, I argue that the consequences of giving up the plural harm principle and holding on to the simple comparative counterfactual analysis of harm are less radical than we may think, in relation to questions about wrongness and responsibility.     

In which direction to move? Facilitative and interference effects of gestures on problem solver's thinking

Recent research shows that co-speech gestures can influence gesturers’ thought. This line of research suggests that the influence of gestures is so strong, that it can wash out and reverse an effect of learning. We argue that these findings need a more robust and ecologically valid test, which we provide in this article. Our results support the claim that gestures not only reflect information in our mental representations, but can also influence gesturer's thought by adding action information to one's mental representation during problem solving (Tower of Hanoi). We show, however, that the effect of gestures on subsequent performance is not as strong as previously suggested. As opposed to what previous research indicates, gestures' facilitative effect through learning was not nullified by the potentially interfering effect on subsequent problem-solving performance of incompatible gestures. To conclude, using gestures during problem solving seems to provide more benefits than costs for task performance.