The Search for Invariance: Repeated Positive Testing Serves the Goals of Causal Learning

Positive testing is characteristic of exploratory behavior, yet it seems to be at odds with the aim of information seeking. After all, repeated demonstrations of one’s current hypothesis often produce the same evidence and fail to distinguish it from potential alternatives. Research on the development of scientific reasoning and adult rule learning have both documented and attempted to explain this behavior. The current chapter reviews this prior work and introduces a novel theoretical account—the Search for Invariance (SI) hypothesis—which suggests that producing multiple positive examples serves the goals of causal learning. This hypothesis draws on the interventionist framework of causal reasoning, which suggests that causal learners are concerned with the invariance of candidate hypotheses. In a probabilistic and interdependent causal world, our primary goal is to determine whether, and in what contexts, our causal hypotheses provide accurate foundations for inference and intervention—not to disconfirm their alternatives. By recognizing the central role of invariance in causal learning, the phenomenon of positive testing may be reinterpreted as a rational information-seeking strategy

Individual and neighborhood-level socioeconomic characteristics in relation to smoking prevalence among black and white adults in the Southeastern United States: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Low individual-level socioeconomic status (SES) is associated with higher prevalence of cigarette smoking. Recent work has examined whether neighborhood-level SES may affect smoking behavior independently from individual-level measures. However, few comparisons of neighborhood-level effects on smoking by race and gender are available.</p> <p>Methods</p> <p>Cross-sectional data from adults age 40-79 enrolled in the Southern Community Cohort Study from 2002-2009 (19, 561 black males; 27, 412 black females; 6, 231 white males; 11, 756 white females) were used in Robust Poisson regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CI) for current smoking in relation to individual-level SES characteristics obtained via interview and neighborhood-level SES characteristics represented by demographic measures from US Census block groups matched to participant home addresses.</p> <p>Results</p> <p>Several neighborhood-level SES characteristics were modestly associated with increased smoking after adjustment for individual-level factors including lower percentage of adults with a college education and lower percentage of owner-occupied households among blacks but not whites; lower percentage of households with interest, dividends, or net rental income among white males; and lower percentage of employed adults among black females.</p> <p>Conclusions</p> <p>Lower neighborhood-level SES is associated with increased smoking suggesting that cessation programs may benefit from targeting higher-risk neighborhoods as well as individuals.</p

Implications of Training in Incremental Theories of Intelligence for Undergraduate Statistics Students

This chapter documents the effects of training in incremental theories of intelligence on students in introductory statistics courses at a liberal arts university in the US. Incremental theories of intelligence examine the beliefs individuals hold of knowledge and how it is attained. An individual with an incremental theory of intelligence believes that intelligence can be developed. The research examined differences by gender in mastery of statistics and attitudes toward statistics for students who received growth mind-set training. A pre-test, post-test design utilised the Students’ Attitudes Toward Statistics© instrument and the Comprehensive Assessment of Outcomes in a first Statistics course. An ANCOVA revealed that females gained more than males on their value of statistics (F(1, 63) 9.40, MSE 3.79, p .003, η2 P 0.134) and decreased less for effort expended to learn statistics (F(1, 63) 4.41, MSE 4.07, p .040, η2 P 0.067). Females also gained mastery of statistical concepts at a greater rate (F(1, 63) 5.30, MSE 0.06, p .025, η2 P 0.080) indicating a possible path to alleviate the under-representation of females in STEM

Molecular Evolution of Ultraspiracle Protein (USP/RXR) in Insects

Ultraspiracle protein/retinoid X receptor (USP/RXR) is a nuclear receptor and transcription factor which is an essential component of a heterodimeric receptor complex with the ecdysone receptor (EcR). In insects this complex binds ecdysteroids and plays an important role in the regulation of growth, development, metamorphosis and reproduction. In some holometabolous insects, including Lepidoptera and Diptera, USP/RXR is thought to have experienced several important shifts in function. These include the acquisition of novel ligand-binding properties and an expanded dimerization interface with EcR. In light of these recent hypotheses, we implemented codon-based likelihood methods to investigate if the proposed shifts in function are reflected in changes in site-specific evolutionary rates across functional and structural motifs in insect USP/RXR sequences, and if there is any evidence for positive selection at functionally important sites. Our results reveal evidence of positive selection acting on sites within the loop connecting helices H1 and H3, the ligand-binding pocket, and the dimer interface in the holometabolous lineage leading to the Lepidoptera/Diptera/Trichoptera. Similar analyses conducted using EcR sequences did not indicate positive selection. However, analyses allowing for variation across sites demonstrated elevated non-synonymous/synonymous rate ratios (dN/dS), suggesting relaxed constraint, within the dimerization interface of both USP/RXR and EcR as well as within the coactivator binding groove and helix H12 of USP/RXR. Since the above methods are based on the assumption that dS is constant among sites, we also used more recent models which relax this assumption and obtained results consistent with traditional random-sites models. Overall our findings support the evolution of novel function in USP/RXR of more derived holometabolous insects, and are consistent with shifts in structure and function which may have increased USP/RXR reliance on EcR for cofactor recruitment. Moreover, these findings raise important questions regarding hypotheses which suggest the independent activation of USP/RXR by its own ligand

Modern tests of Lorentz invariance

Motivated by ideas about quantum gravity, a tremendous amount of effort over the past decade has gone into testing Lorentz invariance in various regimes. This review summarizes both the theoretical frameworks for tests of Lorentz invariance and experimental advances that have made new high precision tests possible. The current constraints on Lorentz violating effects from both terrestrial experiments and astrophysical observations are presented.Comment: Modified and expanded discussions of various points. Numerous references added. Version matches that accepted by Living Reviews in Relativit

Culture or Biology? If this sounds interesting, you might be confused

Culture or Biology? The question can seem deep and important. Yet, I argue in this chapter, if you are enthralled by questions about our biological differences, then you are probably confused. My goal is to diagnose the confusion. In debates about the role of biology in the social world it is easy to ask the wrong questions, and it is easy to misinterpret the scientific research. We are intuitively attracted to what is called psychological essentialism, and therefore interpret what is biological as what can be traced to “essences”. On this interpretation, it would be deep and important to know what about, say, the differences between the genders is biological: it would correspond to what is essential to being a man or being a woman, and be opposed to what is a mere accidental feature that some women or some men have. Yet, the psychological essentialist understanding of ‘biological differences’ is deeply mistaken about biology. It has the wrong conception of biological kinds, of biological heritability, and of how genes and hormones work. Those who argue for an important role of ‘biology’ in the explanation of human differences often see ‘the science’ on their side. But this is false – on the interpretation of ‘biological differences’ that is most intuitive and that makes the question appear to be most interesting. Defenders of ‘biology’ often have the science against them. What is often called ‘biology’ is a myth: a myth created by an intuitive tendency that grotesquely distorts real biological research

Antagonizing retinoic acid receptors increases myeloid cell production by cultured human hematopoietic stem cells

Activities of the retinoic acid receptor (RAR)α and RARγ are important to hematopoiesis. Here, we have investigated the effects of receptor selective agonists and antagonists on the primitive human hematopoietic cell lines KG1 and NB-4 and purified normal human hematopoietic stem cells (HSCs). Agonizing RARα (by AGN195183) was effective in driving neutrophil differentiation of NB-4 cells and this agonist synergized with a low amount (10 nM) of 1α,25-dihydroxyvitamin D(3) to drive monocyte differentiation of NB-4 and KG1 cells. Treatment of cultures of human HSCs (supplemented with stem cell factor ± interleukin 3) with an antagonist of all RARs (AGN194310) or of RARα (AGN196996) prolonged the lifespan of cultures, up to 55 days, and increased the production of neutrophils and monocytes. Slowing down of cell differentiation was not observed, and instead, hematopoietic stem and progenitor cells had expanded in number. Antagonism of RARγ (by AGN205728) did not affect cultures of HSCs. Studies of CV-1 and LNCaP cells transfected with RAR expression vectors and a reporter vector revealed that RARγ and RARβ are activated by sub-nM all-trans retinoic acid (EC(50)–0.3 nM): ~50-fold more is required for activation of RARα (EC(50)–16 nM). These findings further support the notion that the balance of expression and activity of RARα and RARγ are important to hematopoietic stem and progenitor cell expansion and differentiation

Deliberate self-harm and attachment: mediating and moderating roles of depression, anxiety, social support and interpersonal problems among Pakistani school going adolescents

Introduction: In Pakistan there is dearth of research on deliberate self-harm (DSH) and its predictors among adolescents. While the lack of research in Pakistan can be partly attributed to the sacrilegious status, criminalization and stigmatization attached to DSH, it is also an attribute of paucity of Urdu versions of the standardized psychological instruments. Previous research in developed countries has indicated that attachment theory can be used as a useful framework to understand the development of austere psychopathologies like DSH, as well as for studying pathways of interaction of interpersonal and intrapersonal factors of psychopathologies. In this study, standardized psychological instruments are translated into Urdu language as a first step. These instruments are then used to study pathways of interaction of interpersonal and intrapersonal factors of DSH, conceptualized within attachment framework. Method: The study was conducted in two steps. In step 1, Youth Health Risk Behavior Survey (YHRB), Inventory of Interpersonal Problems-32 (IIP-32) and Significant Others Scale (SOS), were translated into Urdu language. Along with these scales, Urdu translated versions of Hospital Anxiety and Depression Scale (HADS), Adolescent Relationship Scales Questionnaire (ARSQ), Life Events scale (LES) from CASE questionnaire and Family Affluence Scale-II (FAS-II) were reviewed for accuracy of translation through expert judgement and psychometric evaluation. Secondly, a cross sectional survey was conducted with 1290 adolescents (10 - 19 years age) using the translated Urdu versions of the instruments and demographic pro forma. Structural equation modelling was used to study the pathways of associations between predictors of DSH. Results: The extensive process of translation resulted in establishment of semantic, content, technical and construct equivalence of the translated instruments with the original English versions. Multiple imputation was performed to account for missing values in SPSS 20. Important structural adaptations were made in the scales based on factor analyses conducted in M plus. After modifications, all scales showed satisfactory CFI (≥ 0.90) and RMSEA (≤ 0.06). Results of the survey indicated that the prevalence of DSH (with, without and ambivalent suicidal intentions) was 7%. Two SEM models were constructed involving both mediation and moderation pathways. Results of Model 1 showed association of attachment with DSH was double mediated by social support, depression and anxiety. Model 2 also confirmed association of attachment with DSH with double mediation through relationship style problems, depression and anxiety. In order to understand the contextual picture of the concepts studied in this research both SEM models were also constructed by controlling for demographic factors. This resulted in confirming age, gender and family affluence as significant contributors but with very small effects. Discussion and conclusion: In the present study translation of the instruments helped in building a reservoir for future research. The results of translation and validation of instruments indicated that cultural differences, language needs and age must be accounted for while using standardized psychological instruments. Taking into consideration specific cultural and demographic background of Pakistan, this study also confirms the key role of attachment in influencing interaction of predictors of DSH. It is suggested that intrapersonal and interpersonal factors are influential points of intervention for designing clinical, school and community based awareness and prevention programs for DSH. The thesis also discusses the implications for policy guidelines along with recommendations for future research and other applications of the study

Seeing the other side: Perspective taking and the moderation of extremity

Recognizing the reasonableness of others' positions is important for conflict reduction, but is notoriously hard. We tested a perspective-taking approach to decreasing attitude entrenchment. Participants were held accountable in a task in which they wrote about a controversial issue from the perspective of a partner with an opposing viewpoint. This approach was effective at changing views on controversial issues-in Study 1 on weight discrimination, an issue participants were unlikely to have thought much about, and in Study 2 on abortion, where beliefs tend to be more deeply held. Studies 3 and 4 showed this change only took place under conditions where participants met the individual with an opposing view in person, and where that individual would see the perspective-taking effort. These results suggest that it is possible to reduce attitude entrenchment by encouraging people to think about the opposing perspective of another, as long as there is real contact and accountability