Reversing Arrows in Mediation Models Does Not Distinguish Plausible Models

Reversing arrows in the classic tri-variate X-M-Y mediation models as a test to check whether one mediation model is superior to another is inadmissible. Presenting evidence that one tri-variate mediation model yields a significant indirect effect, whereas one with some reversed arrows does not, is not proof or even evidence that one model should be preferred. In fact, the significance of the indirect or any other effect can never be used to infer whether one model should be preferred over another, if the models are in the same so-called equivalence class. The practice of running several mediation models with reversed arrows to decide which model to prefer should be abandoned. The only way to choose among equivalent models is through assumptions that are either fulfilled by design features or invoked based on theory. Similar arguments about reversing arrows in mediation models have been made before, but this current work is the first to derive this result analytically for the complete (Markovian) equivalence class of the tri-variate mediation model.     

Violence prevention: Program effects on urban preschool and kindergarten children

This study compares the effectiveness of a violence prevention program with young, at-risk children in two settings. Preschool and kindergarten students, residing in Chicago public-housing developments, participated in a 28-session intervention. Knowledge, behavior problems, and social skills were assessed at pretest and posttest, based on child interviews, teacher ratings, and behavioral observations. Findings suggest that both preschool and kindergarten children demonstrated significant gains in knowledge, based on interview scores, and significant decreases in problem behaviors, based on behavioral observations; however, teacher ratings did not change significantly across time. The discrepancy in findings is explored and implications are discussed.     

Theory and Analysis of Total,Direct, and Indirect Causal Effects

Mediation analysis, or more generally models with direct and indirect effects, are commonly used in the behavioral sciences. As we show in our illustrative example, traditional methods of mediation analysis that omit confounding variables can lead to systematically biased direct and indirect effects, even in the context of a randomized experiment. Therefore, several definitions of causal effects in mediation models have been presented in the literature (Baron &; Kenny, 1986 Baron, R.M., &; Kenny, D.A. (1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic and statistical considerations. Journal of Personality and Social Psychology, 51, 1173–1182. doi:10.1037/0022-3514.51.6.1173[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Imai, Keele, &; Tingley, 2010 Imai, K., Keele, L., &; Tingley, D. (2010). A general approach to causal mediation analysis. Psychological Methods, 15, 309–334. doi:10.1037/a0020761[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Pearl, 2012 Pearl, J. (2012). The causal mediation formula: A guide to the assessment of pathways and mechanisms. Prevention Science, 13, 426–436. doi:10.1007/s11121-011-0270-1[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). We illustrate the stochastic theory of causal effects as an alternative foundation of causal mediation analysis based on probability theory. In this theory we define total, direct, and indirect effects and show how they can be identified in the context of our illustrative example. A particular strength of the stochastic theory of causal effects are the causality conditions that imply causal unbiasedness of effect estimates. The causality conditions have empirically testable implications and can be used for covariate selection. In the discussion, we highlight some similarities and differences of the stochastic theory of causal effects with other theories of causal effects.     

Bigger knows better: Young children selectively learn rule games from adults rather than from peers

Preschoolers' selective learning from adult versus peer models was investigated. Extending previous research, children from age 3 were shown to selectively learn simple rule games from adult rather than peer models. Furthermore, this selective learning was not confined to preferentially performing certain acts oneself, but more specifically had a normative dimension to it: children understood the way the adult demonstrated an act not only as the better one, but as the normatively appropriate/correct one. This was indicated in their spontaneous normative interventions (protest, critique, etc.) in response to third party acts deviating from the one demonstrated by the adult model. Various interpretations of these findings are discussed in the broader context of the development of children's social cognition and cultural learning.     

Extrinsic rewards undermine altruistic tendencies in 20-month-olds

The current study investigated the influence of rewards on very young children's helping behavior. After 20-month-old infants received a material reward during a treatment phase, they subsequently were less likely to engage in further helping during a test phase as compared with infants who had previously received social praise or no reward at all. This so-called overjustification effect suggests that even the earliest helping behaviors of young children are intrinsically motivated and that socialization practices involving extrinsic rewards can undermine this tendency.     

Speaking after the Phenomenon: the Promise of Things and the Future of Phenomenology

Phenomenology speaks not directly of phenomena but rather of the appearing of phenomena. In so speaking it moves from the level of things with generic or proper names to the level of universal terms. In speaking and thinking the phenomenon Phenomenology comes “after” in the twofold sense of being too late and desiring for that which is to come. This paper explores this place of phenomenology with respect to the relation of faith and reason, the manner of speaking phenomenologically and the affective and temporal situation of experience. Drawing on the pre-modern concept of the transcendentals and on an account of emphatic consciousness of things, this article argues that the future of phenomenology is as a form of metaphysics which remains focused on experience and the “promise” of things that guides and structures perception.     

Social Support and Neighborhood Stressors Among African American Youth: Networks and Relations to Self-Worth

Although neighborhood stressors have a negative impact on youth, and social support can play a protective role, it is unclear what types and sources of social support may contribute to positive outcomes among at-risk youth. We examined the influences of neighborhood disadvantage and social support on global self-worth among low-income, urban African American youth, both concurrently and longitudinally. We examined social support from both a structural and functional perspective, and tested the main-effects and the stress-buffering models of social support. Participants included 82–130 youth, in 6th–8th grade, who completed self-report measures. Network support results suggest participants received emotional, tangible, and informational support most often from mothers and other female relatives, with friends, fathers, and teachers also playing important roles. Model testing accounted for neighborhood stressors and support from various sources, revealing support from close friends was associated with concurrent self-worth; whereas, parent support predicted self-worth longitudinally, above and beyond initial levels of self-worth. The findings provide evidence for the main-effects model of social support and not the stress-buffering model. Our findings illustrate the importance of extended family networks and the types of support that youth rely upon in African American impoverished communities, as well as how support contributes to global self-worth. Implications and suggestions for future research and intervention are discussed.     

Frequency of nightmares and gender significantly predict distressing dreams of German athletes before competitions or games

Important sports events are highlights and stressful situations in every athlete's career. This stress might alter the dream content of athletes and consequently evoke disturbed dreaming. In this study, the authors asked 840 German athletes from various sports about distressing dreams on the nights before an important competition or game. About 15% of the athletes stated that they experienced at least 1 distressing dream before an important competition or game during the preceding 12 months. An almost equal number of athletes reported at least 1 distressing dream in their sports career. With respect to the base rate, in about 3% of the events a distressing dream occurred. Reported dream content referred mainly to athletic failure. The main risk factor for an athlete experiencing a distressing dream before a competition appears to be the frequency of experienced nightmares in general. Future research should use diary techniques to study the impact of distressing dreams on the next-day athletic performance in a competition or game.