Influence of swimming speed on inter-arm coordination in competitive unilateral arm amputee front crawl swimmers

This study examined the effect of swimming speed on inter-arm coordination and the inter-relationships between swimming speed, inter-arm coordination, and other stroke parameters, in a group of competitive unilateral arm amputee front crawl swimmers. Thirteen highly-trained swimmers were filmed underwater during a series of 25-m front crawl trials of increasing speed. Arm coordination for both arms was quantified using an adapted version of the Index of Coordination. Inter-arm coordination of the amputee swimmers did not change as swimming speed was increased up to maximum. Swimmers showed significantly more catch-up coordination of their affected-arm compared to their unaffected-arm. When sprinting, the fastest swimmers used higher stroke frequencies and less catch-up of their affected-arm than the slower swimmers. Unilateral arm-amputees used an asymmetrical strategy for coordinating their affected-arm relative to their unaffected-arm to maintain the stable repetition of their overall arm stroke cycle. When sprinting, the attainment of a high stroke frequency is influenced mainly by the length of time the affected-arm is held in a stationary position in front of the body before pulling. Reducing this time delay appears to be beneficial for successful swimming performance.     

Reintegrative Shaming Theory, moral emotions and bullying

This article investigates the usefulness of Reintegrative Shaming Theory (RST) in explaining the bullying of siblings in families and peers in schools. Questionnaires were completed by 182 children aged 11-12 years in ten primary schools in Nicosia, Cyprus, about sibling and peer bullying. A vignette-based methodology was used to investigate children's expectations of the type of shaming their parents would offer in response to their possible wrong doing. Children were also asked questions about the emotions they would have felt (i.e. shame, remorse, guilt or anger) if they were in the position of the child in the vignette. The level of bonding toward each parent was also examined. In agreement with the theory, a path analysis showed that mother bonding influenced children's expectations of the type of shaming offered by parents. Disintegrative shaming (i.e. shaming offered in a stigmatizing or rejecting way) had a direct effect on the way children managed their shame. Shame management directly influenced sibling and peer bullying. Father bonding had no direct or indirect effects in the model. Against the theory, reintegrative shaming (i.e. shaming offered in the context of approving the wrongdoer while rejecting the wrongdoing) did not have a direct effect on shame management. Beyond the postulates of RST, mother bonding-a plausible indicator of family functioning-had a direct effect on sibling and peer bullying. Mother bonding had a stronger effect for boys than for girls. It is concluded that RST is useful in explaining the link between family factors and bullying, and that RST has cross-cultural applicability.     

Boys Who Join Gangs: A Prospective Study of Predictors of First Gang Entry

In a representative sample of boys who were in the 7th grade of an urban public school system at the start of a 6-year longitudinal study, more African American boys (23.8%) than non-Hispanic White boys (3.9%) had entered an antisocial gang by age 19. There were too few White gang members to study, but among African American boys, first gang entry was predicted prospectively by both baseline conduct disorder (CD) behaviors and increasing levels of CD behaviors prior to gang entry. This suggests that gang entry may be a further developmental step for some boys who are already on a trajectory of worsening antisocial behavior. Having friends prior to gang entry who engaged in aggressive delinquency increased the risk of gang entry further, but only during early adolescence. Family income and parental supervision also independently predicted gang entry, but the direction of their influences depended on the youth's age.     

Stereotype threat and group differences in test performance: a question of measurement invariance

Studies into the effects of stereotype threat (ST) on test performance have shed new light on race and sex differences in achievement and intelligence test scores. In this article, the authors relate ST theory to the psychometric concept of measurement invariance and show that ST effects may be viewed as a source of measurement bias. As such, ST effects are detectable by means of multi-group confirmatory factor analysis. This enables research into the generalizability of ST effects to real-life or high-stakes testing. The modeling approach is described in detail and applied to 3 experiments in which the amount of ST for minorities and women was manipulated. Results indicate that ST results in measurement bias of intelligence and mathematics tests.     

Children's antisocial behavior, mental health, drug use, and educational performance after parental incarceration: a systematic review and meta-analysis

Unprecedented numbers of children experience parental incarceration worldwide. Families and children of prisoners can experience multiple difficulties after parental incarceration, including traumatic separation, loneliness, stigma, confused explanations to children, unstable childcare arrangements, strained parenting, reduced income, and home, school, and neighborhood moves. Children of incarcerated parents often have multiple, stressful life events before parental incarceration. Theoretically, children with incarcerated parents may be at risk for a range of adverse behavioral outcomes. A systematic review was conducted to synthesize empirical evidence on associations between parental incarceration and children's later antisocial behavior, mental health problems, drug use, and educational performance. Results from 40 studies (including 7,374 children with incarcerated parents and 37,325 comparison children in 50 samples) were pooled in a meta-analysis. The most rigorous studies showed that parental incarceration is associated with higher risk for children's antisocial behavior, but not for mental health problems, drug use, or poor educational performance. Studies that controlled for parental criminality or children's antisocial behavior before parental incarceration had a pooled effect size of OR = 1.4 (p < .01), corresponding to about 10% increased risk for antisocial behavior among children with incarcerated parents, compared with peers. Effect sizes did not decrease with number of covariates controlled. However, the methodological quality of many studies was poor. More rigorous tests of the causal effects of parental incarceration are needed, using randomized designs and prospective longitudinal studies. Criminal justice reforms and national support systems might be needed to prevent harmful consequences of parental incarceration for children.     

Stability in aggression revisited

Research on the stability of aggression tends to show patterns of continuity and to a lesser extent discontinuity. In this study, we provide a review of research published in four specific journals that target the stability of aggression across distinct periods of the life course. Findings from these studies identify considerable support for both instability and stability of aggression, but with some unique findings related to aggression among females as well as adult-onset aggression. The review closes with an original empirical analysis using longitudinal data from the Cambridge Study in Delinquent Development linking teacher-rated aggression in childhood/adolescence to official conviction records in mid-adulthood, the findings of which suggest a strong degree of continuity in aggression/antisocial behavior among the most aggressive youths/chronic offenders. Conclusions and directions for future research are also discussed.     

Exercising Doxastic Freedom

This paper defends the possibility of doxastic freedom, arguing that doxastic freedom should be modelled not on freedom of action but on freedom of intention. Freedom of action is exercised by agents like us, I argue, through voluntary control. This involves two conditions, intentions‐reactivity and reasons‐reactivity, that are not met in the case of doxastic states. Freedom of intention is central to our agency and to our moral responsibility, but is not exercised through voluntary control. I develop and defend an account of freedom of intention, arguing that constitutive features of intention ensure that freedom of intention cannot require voluntary control. Then I show that an analogous argument can be applied to doxastic states. I argue that if we had voluntary control of intentions or of doxastic states, this would actually undermine our freedom.     

Hemispheric differences in specificity effects in talker identification

In the visual domain, Marsolek and colleagues (1999, 2008) have found support for two dissociable and parallel neural subsystems underlying object and shape recognition: an abstract-category subsystem that operates more effectively in the left cerebral hemisphere (LH), and a specific-exemplar subsystem that operates more effectively in the right cerebral hemisphere (RH). Evidence of this asymmetry has been observed in priming specificity for linguistic (words, pseudoword forms) and nonlinguistic (objects) stimuli. In the auditory domain, the authors previously found hemispheric asymmetries in priming effects for linguistic (spoken words) and nonlinguistic (environmental sounds) stimuli. In the present study, the same asymmetrical pattern was observed in talker identification by means of two long-term repetition-priming experiments. Both experiments consisted of a familiarization phase and a final talker identification test phase, using sentences as stimuli. The results showed that specificity effects (an advantage for same-sentence priming, relative to different-sentence priming) emerged when the target stimuli were presented to the left ear (RH), but not when the target stimuli were presented to the right ear (LH). Taken together, this consistent asymmetrical pattern of data from both domains-visual and auditory-may be indicative of a more general property of the human perceptual processing system. Theoretical implications are discussed.     

Testing and modelling non‐normality within the one‐factor model

Maximum likelihood estimation in the one‐factor model is based on the assumption of multivariate normality for the observed data. This general distributional assumption implies three specific assumptions for the parameters in the one‐factor model: the common factor has a normal distribution; the residuals are homoscedastic; and the factor loadings do not vary across the common factor scale. When any of these assumptions is violated, non‐normality arises in the observed data. In this paper, a model is presented based on marginal maximum likelihood to enable explicit tests of these assumptions. In addition, the model is suitable to incorporate the detected violations, to enable statistical modelling of these effects. Two simulation studies are reported in which the viability of the model is investigated. Finally, the model is applied to IQ data to demonstrate its practical utility as a means to investigate ability differentiation.     

Self-knowledge and the KK principle

I argue that a version of the so-called KK principle is true for principled epistemic reasons; and that this does not entail access internalism, as is commonly supposed, but is consistent with a broad spectrum of epistemological views. The version of the principle I defend states that, given certain normal conditions, knowing p entails being in a position to know that you know p. My argument for the principle proceeds from reflection on what it would take to know that you know something, rather than from reflection on the conditions for knowledge generally. Knowing that you know p, it emerges, is importantly similar to cases of psychological self-knowledge like knowing that you believe p: it does not require any grounds other than your grounds for believing p itself. In so arguing, I do not rely on any general account of knowledge, but only on certain plausible and widely accepted epistemological assumptions.