Effects of caste, birth season, and family income on digit ratios.

OBJECTIVES: The contributions of latitude and ethnicity in the determination of cross-society differences in digit ratios are unclear. In India, different castes (endogamous groups) have been living in the same areas (villages or towns) for the last 1500 years and, therefore, these groups may have different gene pools without a latitude-related difference component. Thus, in the present study, we studied the effect of caste on digit ratios. We also studied the effects of sex, birth season, and family income on digit ratios. METHODS: We selected a sample of 301 college students (age: M = 19.9 years, SD = 2.63) in Muzaffarnagar city of western Uttar Pradesh, India, and asked participants for information regarding their birth month, religion, caste, and monthly family income. We measured participants' dorsal and palmar digit lengths (of all fingers, except the thumb, in both hands) using vernier calipers of 0.01 mm accuracy. RESULTS: Other backward castes (intermediate castes) had longer digit lengths than general castes (upper castes), scheduled castes (lower castes), and Muslims. However, there was no difference in digit ratios of caste groups (scheduled castes vs. other backward castes vs. general castes vs. Muslims) or specific castes (Chamar-Jatav vs. Jat vs. Pandit-Tyagi). Winter-born women had lower left dorsal 2D:4D and 3D:4D ratios than summer-born women. Family income was related to higher dorsal 2D:4D and 3D:4D ratios among women. Moreover, in dorsal digit ratios, sex difference (men < women) occurred in digit ratios constituting digit 5, whereas, in palmar digit ratios, sex difference occurred in digit ratios constituting digit 2. CONCLUSIONS: The present study suggests that endogamy-led genetic difference in ethnic/caste groups is not a determinant, whereas birth season (i.e., the exposure to sunlight) and family income might be determinants of digit ratios. In addition, compared to palmar digit ratios, dorsal digit ratios are better markers of sexual dimorphism.

The relationships of family income and caste-status with religiousness: Mediation role of intolerance of uncertainty.

The relationship between lower socioeconomic status (SES) and religiousness is well known; however, its (psychological mediation) mechanism is not clear. In the present study, we studied the mediation role of intolerance of uncertainty (IU; a personality measure of self-uncertainty) in the effect of SES on religiousness and its dimensions (i.e., believing, bonding, behaving, and belonging), in two different samples (students sample, N = 868, and community sample, N = 250), after controlling the effects of factors like age, sex, handedness, and self-reported risk-taking. The results showed that IU mediated the effects of lower family income and lower caste status (in students' sample only) on religiousness and its dimensions; higher caste status had a direct effect on religiousness (and its dimensions), and; among the sub-factors of IU, only prospective IU affected religiousness. Thus, along with showing that IU is a mediator of the effects of lower family income and lower caste status on religiousness, the present study supports the contention that religiousness is a latent variable that varied factors can independently initiate. Moreover, the present study suggests a nuanced model of the relationship between the hierarchical caste system and religiousness.

The Handedness Index Practical Task (HI20): An economic behavioural measure for assessing manual preference.

ABSTRACTBecause self-report hand preference measures are limited to investigating cognitive aspects of manual laterality, valid, easy-to-administer and economic behavioural methods are needed for capturing the motoric component of handedness. Therefore, this study introduces the Handedness Index Practical Task (HI20) and tests it in a sample of 206 students (Mage = 23.79 years, SDage = 3.01 years), half of whom were self-specified left-handers. After confirming good reliabilities at the subscale and total scale levels, k-means cluster analysis allowed an empirically based partitioning of test subjects into left- (n = 72), mixed- (n = 23) and right-handers (n = 111). To validate this categorization and the HI20 index, data were compared with the Edinburgh Handedness Inventory (EHI), EHI-short, HI22 and hand grip strength. The congruency between the HI20 clusters and alternative categorizations ranged from 95.6% to 84.0%, while the clusters explained large portions of variance in grip strength differences. The HI20 sub- and total scores showed strong correlations with other measures of lateral preference. Altogether, the freely available HI20 emerges as a reliable and valid alternative for behavioural handedness assessment, whose power lies in explaining differential hand use patterns and enabling fine-grained examinations of handedness.

Harnessing the Fifth Element of Distributional Statistics for Psychological Science: A Practical Primer and Shiny App for Measures of Statistical Inequality and Concentration.

Although distributional inequality and concentration are important statistical concepts in many research fields (including economics, political and social science, information theory, and biology and ecology), they rarely are considered in psychological science. This practical primer familiarizes with the concepts of statistical inequality and concentration and presents an overview of more than a dozen useful, popular measures of inequality (including the Gini, Hoover, Rosenbluth, Herfindahl-Hirschman, Simpson, Shannon, generalized entropy, and Atkinson indices, and tail ratios). Additionally, an interactive web application (R Shiny) for calculating and visualizing these measures, with downloadable output, is described. This companion Shiny app provides brief introductory vignettes to this suite of measures, along with easy-to-understand user guidance. The Shiny app can readily be used as an intuitively accessible, interactive learning and demonstration environment for teaching and exploring these methods. We provide various examples for the application of measures of inequality and concentration in psychological science and discuss venues for further development.

Research practices and statistical reporting quality in 250 economic psychology master's theses: a meta-research investigation.

The replicability of research findings has recently been disputed across multiple scientific disciplines. In constructive reaction, the research culture in psychology is facing fundamental changes, but investigations of research practices that led to these improvements have almost exclusively focused on academic researchers. By contrast, we investigated the statistical reporting quality and selected indicators of questionable research practices (QRPs) in psychology students' master's theses. In a total of 250 theses, we investigated utilization and magnitude of standardized effect sizes, along with statistical power, the consistency and completeness of reported results, and possible indications of p-hacking and further testing. Effect sizes were reported for 36% of focal tests (median r = 0.19), and only a single formal power analysis was reported for sample size determination (median observed power 1 - ß = 0.67). Statcheck revealed inconsistent p-values in 18% of cases, while 2% led to decision errors. There were no clear indications of p-hacking or further testing. We discuss our findings in the light of promoting open science standards in teaching and student supervision.

Brief assessment of schizotypal traits: A multinational study.

The Schizotypal Personality Questionnaire-Brief (SPQ-B) was developed with the aim of examining variations in healthy trait schizotypy, as well as latent vulnerability to psychotic-spectrum disorders. No previous study has studied the cross-cultural validity of the SPQ-B in a large cross-national sample. The main goal of the present study was to analyze the reliability and the internal structure of SPQ-B scores in a multinational sample of 28,426 participants recruited from 14 countries. The mean age was 22.63years (SD=7.08; range 16-68years), 37.7% (n=10,711) were men. The omega coefficients were high, ranging from 0.86 to 0.92 for the total sample. Confirmatory factor analysis revealed that SPQ-B items were grouped either in a theoretical structure of three first-order factors (Cognitive-Perceptual, Interpersonal, and Disorganized) or in a bifactor model (three first-order factors plus a general factor of schizotypal personality). In addition, the results supported configural but not strong measurement invariance of SPQ-B scores across samples. These findings provide new information about the factor structure of schizotypal personality, and support the validity and utility of the SPQ-B, a brief and easy tool for assessing self-reported schizotypal traits, in cross-national research. Theoretical and clinical implications for diagnostic systems, psychosis models, and cross-national mental health strategies are derived from these results.

Digit Ratio (2D:4D) Predicts Self-Reported Measures of General Competitiveness, but Not Behavior in Economic Experiments.

The ratio of index finger length to ring finger length (2D:4D) is considered to be a putative biomarker of prenatal androgen exposure (PAE), with previous research suggesting that 2D:4D is associated with human behaviors, especially sex-typical behaviors. This study empirically examines the relationship between 2D:4D and individual competitiveness, a behavioral trait that is found to be sexually dimorphic. We employ two related, but distinct, measures of competitiveness, namely behavioral measures obtained from economic experiments and psychometric self-reported measures. Our analyses are based on two independent data sets obtained from surveys and economic experiments with 461 visitors of a shopping mall (Study I) and 617 university students (Study II). The correlation between behavior in the economic experiment and digit ratios of both hands is not statistically significant in either study. In contrast, we find a negative and statistically significant relationship between psychometric self-reported measures of competitiveness and right hand digit ratios (R2D:4D) in both studies. This relationship is especially strong for younger people. Hence, this study provides some robust empirical evidence for a negative association between R2D:4D and self-reported competitiveness. We discuss potential reasons why digit ratio may relate differently to behaviors in specific economics experiments and to self-reported general competitiveness.

Suicidal Behavior and Psychological Distress in University Students: A 12-nation Study.

This study investigated the prevalence of suicidal behavior and psychological distress in university students across 12 nations. A total of 5,572 university students from 12 countries were surveyed about suicide ideation, suicide attempts, and psychological distress by means of a self-administered questionnaire. Almost 29% of the samples reported having contemplated suicide and 7% reported attempting suicide. Of the total sample, 51.1% scored above the General Health Questionnaire-12 ≥ 3 cut-off points, 41.6% above the GHQ-12 ≥ 4 cut-off points, and 33.8% scored above the GHQ-12 ≥ 5 cut-off points. While odds of suicide ideation were elevated in Austria and the UK, reduced ORs were detected for China, Italy, Saudi Arabia, Tunisia, and Turkey. Similarly, while odds of suicide attempt were high in Jordan, Palestine, Saudi Arabia, and to some extent in Turkey, reduced ORs were observed for Austria, China, Italy, Japan and the United States. Elevated ORs for psychological distress were seen in Japan, Jordan, Palestine, Saudi Arabia, Tunisia, and Turkey but reduced ORs were noted in Austria, China, Iran, Italy, and the United States. Psychological distress was strongly associated with reports of suicide ideation and attempts. Suicide ideation, suicide attempt, and psychological distress are common in university students but their rates vary depending on the sociocultural context. Due attention should be devoted to the mental health needs of young adults enrolled in higher educational institutions and more cross-cultural research is warranted to better understand the etiology of the observed intersocietal variations in suicidal behavior and psychological distress.

Effects of Initial Values and Convergence Criterion in the Two-Parameter Logistic Model When Estimating the Latent Distribution in BILOG-MG 3.

Parameters of the two-parameter logistic model are generally estimated via the expectation-maximization algorithm, which improves initial values for all parameters iteratively until convergence is reached. Effects of initial values are rarely discussed in item response theory (IRT), but initial values were recently found to affect item parameters when estimating the latent distribution with full non-parametric maximum likelihood. However, this method is rarely used in practice. Hence, the present study investigated effects of initial values on item parameter bias and on recovery of item characteristic curves in BILOG-MG 3, a widely used IRT software package. Results showed notable effects of initial values on item parameters. For tighter convergence criteria, effects of initial values decreased, but item parameter bias increased, and the recovery of the latent distribution worsened. For practical application, it is advised to use the BILOG default convergence criterion with appropriate initial values when estimating the latent distribution from data.

National intelligence estimates and the Failed State Index.

Across 177 countries around the world, the Failed State Index, a measure of state vulnerability, was reliably negatively associated with the estimates of national intelligence. Psychometric analysis of the Failed State Index, compounded of 12 social, economic, and political indicators, suggested factorial unidimensionality of this index. The observed correspondence of higher national intelligence figures to lower state vulnerability might arise through these two macro-level variables possibly being proxies of even more pervasive historical and societal background variables that affect both.

Further investigation of the validity and reliability of the photographic figure rating scale for body image assessment.

Previous studies have not fully investigated the psychometric properties of the Photographic Figure Rating Scale (PFRS). In 2 studies, we report on the test-retest reliability and convergent validity of ratings derived from the PFRS. In Study 1, 322 female university students in Britain provided self-ratings on the PFRS and objectively measured body mass index (BMI); a subsample of 132 women also completed the task after 5 weeks. In Study 2, 243 women from the community in Austria completed the PFRS along with a battery of other body image scales. Results of Study 1 showed that ratings on the PFRS had good test-retest reliability (all rs > .87) and good convergent validity in relation to BMI. Results of Study 2 showed that PFRS-derived body dissatisfaction scores were significantly correlated with a range of body image variables. These results provide evidence for the convergent validity and good test-retest reliability of the PFRS.

Suicide rates in the national and expatriate population in Dubai, United Arab Emirates.

BACKGROUND: Reports on suicide from the Gulf region are scarce. Dubai is a city with a large expatriate population. However, total and gender-specific suicide rates for the national and expatriate populations are not known. AIMS: To investigate total and gender-specific suicide rates in the national and expatriate population in Dubai and to elicit socio-demographic characteristics of suicide victims. METHODS: Registered suicides in Dubai from 2003 to 2009, and aggregated socio-demographic data of suicide victims were analysed. Suicide rates per 100,000 population were calculated. RESULTS: Suicide rate among expatriates (6.3/100,000) was seven times higher than the rate among the nationals (0.9/100,000). In both groups, male suicide rate was more than three times higher than the female rate. Approximately three out of four expatriate suicides were committed by Indians. The majority of suicide victims were male, older than 30 years, expatriate, single and employed, with an education of secondary school level and below. CONCLUSION: Further research on risk factors for and protective factors against suicide, particularly among the expatriate population, is needed. Epidemiological monitoring of suicide trends at the national level and improvement of UAE suicide statistics would provide useful information for developing suicide prevention strategies.

Big five personality factors and suicide rates in the United States: a state-level analysis.

Partly replicating findings from several cross-national studies (of Lester and of Voracek) on possible aggregate-level associations between personality and suicide prevalence, state-level analysis within the United States yielded significantly negative associations between the Big Five factor of Neuroticism and suicide rates. This effect was observed for historical as well as contemporary suicide rates of the total or the elderly population and was preserved with controls for the four other Big Five factors and measures of state wealth. Also conforming to cross-national findings, the Big Five factors of Agreeableness and Extraversion were negatively, albeit not reliably, associated with suicide rates.

The gap between suicide characteristics in the print media and in the population.

BACKGROUND: Programmes to educate media professionals about suicide are increasingly established, but information about which suicide cases are most likely to be reported in the mass media is sparse. METHODS: We applied binomial tests to compare frequencies of social characteristics of all domestic suicides in the 13 largest Austrian print media in 2005 with frequencies of suicide characteristics in the population. Additionally, each reported suicide case was linked to its respective entry in the suicide database. We performed a logistic regression analysis, with presence of an article as outcome, and sex of the suicide case, age, religious affiliation, family status, conduction of an autopsy and location of the suicide as explaining variables. Time of the year and federal state where the suicide happened was controlled for. RESULTS: Binomial tests showed that suicides involving murder or murder attempt were over-represented in the media. Reporting on mental disorders was under-represented. In the regression analysis, the likelihood of a report was negatively associated with the age of suicide cases. Foreign citizenship was a further predictor of a suicide report. The methods of drowning, jumping, shooting and rare methods were more likely to be reported than hanging, which is the most frequent suicide method in Austria. CONCLUSIONS: Suicide characteristics in the media are not representative of the population. The identified discrepancies provide a basis for tailor-made education of mass media professionals.

Demographic correlates of just world and unjust beliefs in an Austrian sample.

320 Viennese adult participants (47.5% female) in a population sample completed two questionnaires measuring just world beliefs that were scored separately for just and unjust world beliefs. The study aimed to investigate the role of sex and age, as well as religious and political beliefs on just and unjust world beliefs. Older males who identified with a more left-wing political orientation tended to have lower scores on just world beliefs on Rubin and Peplau's scale, while better educated people tended to score lower on the unjust world subscale on both scales, although both predictors explained less than 6% of the variance in scores.

Suicide rates, national intelligence estimates, and differential K theory.

In a nation sample of 75 countries around the world, higher suicide rates of the total male, and female population corresponded to higher levels on the superordinate K factor from differential K theory, thought to reflect a set of mutually interrelated life history and reproductive strategy traits. Countries ranking high on suicide rates concurrently ranked high on national intelligence estimates, longevity, and affluence, whilst low on rates of births, infant mortality, HIV/AIDS, and crimes (rape, serious assault, and homicide). These findings integrate previously reported positive population-level associations between suicide rates and cognitive ability variables into the conceptual space of differential K theory. The propensity toward suicidal behavior is a positive correlate of the K superfactor.

Testing the Finno-Ugrian Suicide Hypothesis: geographic variation of elderly suicide rates across Europe.

The pattern of geographic variation in European suicide rates in the high-risk group of individuals aged 65 years and over was investigated, in order to provide a further test of the Finno-Ugrian Suicide Hypothesis, i.e. the assumption that genetic differences between populations may partially account for spatial differences seen in the suicide prevalence. National suicide rates (average of 1970-2002) of the elderly from 34 European countries were regressed on geographic position terms, i.e. capital cities' latitude and longitude, along with transformations (e.g. squared latitude) and interaction terms (e.g. latitude multiplied with longitude) of these, which statistically modeled various possible geographic gradients in the suicide rates. In these regression models, the strongest and statistically significant predictor of elderly suicide rates was an interaction term of squared latitude multiplied with longitude, indicating that suicide rates increased to the northeast. This accounted for 13.8% (total), 20.8% (males) and 11.6% (females) of the cross-national variance in elderly suicide rates. No further geographic position term accounted for a significant increment of further variance in suicide rates over and above this predictor. Controls for national quality of living conditions and alcohol consumption rates left these results essentially unchanged. Replicating previous evidence based on suicide rates of the general population, suicide rates of the elderly show a northeastern gradient across Europe. This J-shaped belt of high-suicide-rate countries spans from Central Europe (Austria, Hungary and Slovenia) to Northeastern Europe (Finland and the Baltic countries). There are early historical and genetic communalities among the populations inhabiting this area, but, in terms of culture, recent history, political systems and socioeconomic factors, there is great diversity between these countries. The current findings thus add to cumulated empirical evidence consistent with the Finno-Ugrian Suicide Hypothesis.

Why can't a man be more like a woman? Sex differences in Big Five personality traits across 55 cultures.

Previous research suggested that sex differences in personality traits are larger in prosperous, healthy, and egalitarian cultures in which women have more opportunities equal with those of men. In this article, the authors report cross-cultural findings in which this unintuitive result was replicated across samples from 55 nations (N = 17,637). On responses to the Big Five Inventory, women reported higher levels of neuroticism, extraversion, agreeableness, and conscientiousness than did men across most nations. These findings converge with previous studies in which different Big Five measures and more limited samples of nations were used. Overall, higher levels of human development--including long and healthy life, equal access to knowledge and education, and economic wealth--were the main nation-level predictors of larger sex differences in personality. Changes in men's personality traits appeared to be the primary cause of sex difference variation across cultures. It is proposed that heightened levels of sexual dimorphism result from personality traits of men and women being less constrained and more able to naturally diverge in developed nations. In less fortunate social and economic conditions, innate personality differences between men and women may be attenuated.

Regional intelligence and suicide rate: new data for Australia and a synthesis of research.

Previous research has shown for the most part positive correlations between intelligence and suicide prevalence on the national level. However, this study found proxies for regional intelligence in Australia (international average domain scores from the PISA 2000 study) to be significantly negatively correlated with the total, male, and female suicide rates of the different administrative divisions of Australia, and this finding was independent of regional wealth. A research synthesis of the current results and those from similar studies of other countries (positive correlations for Austria, Belarus, The British Isles, Denmark, and The Netherlands; inconclusive findings for France, Germany, and the USA) was conducted. This synthesis of research findings showed that positive ecological correlations of intelligence with suicide rate were more likely observed for nations with higher suicide rates and poorer general living conditions, whereas there was no relation with national IQ.

The nexus of suicide prevalence, helping behavior, pace of life, affluence, and intelligence: contrary results from comparisons across nations and within the United States.

This study examined interrelations among suicide prevalence, affluence, intelligence, pace of life, and helping behavior on the level of aggregate analysis, both cross-nationally and within the USA, using four extant data sets (8, 15, and 29 countries; and 17 U.S. states) for the latter two variables. Pertaining to the association of suicide rates with pace of life, the results replicated discrepant previous findings of Lester. Across nations, suicide is more prevalent in populations living in faster environments, whereas within the USA suicide rates are higher in slower environments. Further, seen from an international perspective, there appears to be a nexus of variables, such that more people tend to commit suicide in the more affluent and faster environments which are populated by more intelligent, but less friendly, individuals. Within the USA, the direction of the correlations of suicide prevalence with these four variables is exactly reversed. Possible reasons for these opposed findings and implications for research are discussed.