Some notes and speculations about various topics. ||| Gegenwärtig - vorübergehend -
wohl eher eine Gedankensammlung als ein Naturwissenschaftsblog. Das Konzept eines "Naturwissenschaftsblogs" wird erst im kommenden Jahr (2018/2019) Umsetzung finden.
In this essay, we follow up on the work of other scholars who have recently cautioned
about the dangers of ideological uniformity in the social sciences. We forward the
paranoid egalitarian meliorist (PEM) model to help account for bias in the social
sciences. Paranoid is not a pejorative term, but describes a sensitivity to perceived
threats to egalitarian meliorism. We argue (1) that many social scientists are paranoid
egalitarian meliorists; (2) that they are therefore very sensitive to threats to a sacred
egalitarian narrative; (3) that this sensitivity may be excessive (at least in the domain of
science) and may cause researchers to unfairly reject research that challenges
egalitarianism; (4) that this may then lead to the marginalization of individuals who
forward controversial theories and/or data; and (5) that these tendencies lead to bias in
the social sciences.
This study investigated differences in cognitive performance between middle-aged adults with and without a lifetime history of mood disorder features, adjusting for a range of potential confounders.
Cross-sectional analysis of baseline data from the UK Biobank cohort. Adults aged 40–69 (n = 143,828) were assessed using measures of reasoning, reaction time and memory. Self-reported data on lifetime features of major depression and bipolar disorder were used to construct groups for comparison against controls. Regression models examined the association between mood disorder classification and cognitive performance, adjusting for sociodemographic, lifestyle and clinical confounders.
Inverse associations between lifetime history of bipolar or severe recurrent depression features and cognitive performance were attenuated or reversed after adjusting for confounders, including psychotropic medication use and current depressive symptoms. Participants with a lifetime history of single episode or moderate recurrent depression features outperformed controls to a small (but statistically significant) degree, independent of adjustment for confounders. There was a significant interaction between use of psychotropic medication and lifetime mood disorder features, with reduced cognitive performance observed in participants taking psychotropic medication.
In this general population sample of adults in middle age, lifetime features of recurrent depression or bipolar disorder were only associated with cognitive impairment within unadjusted analyses. These findings underscore the importance of adjusting for potential confounders when investigating mood disorder-related cognitive function.
Does gender inequality moderate sex differences in sport across countries? Shea M Balish, Robert Deaner, Daniel R Rainham, Chris M Blanchard (2015) Abstract
Although sex differences in preferences for sport are well established, there are competing hypotheses regarding their origins. The Spectator Lek Hypothesis maintains that sex differences in preferences for sport are partly evolved and thus should be universal or near universal, whereas socio-constructivist hypotheses argue that such sex differences are entirely socially constructed and thus should vary as a function of a society's gender inequality. To test these competing hypotheses, cross-national nested data were acquired from the International Social Survey Program (ss = 49,729, ncountries = 34). Non-linear hierarchal Bernoulli modelling was employed to examine if sex differences in sport participation, fandom, and reasons for participating in sport are universal or near universal, and if there is a moderating effect of countries' gender inequality. Our findings indicate that gender inequality is associated with increased sex differences in sport, albeit marginally and only for some sport behaviours. However, even when accounting for the moderating effect of gender inequality, males are more likely to report general sport participation (OR = 4.09, 95% CI = 3.13-5.34), team sport participation (OR = 4.19, 95% CI = 3.13-5.34), watching sport on television (OR = 2.32, 95% CI = 1.69-3.17), to agree that they play sport to compete (OR = 2.03, 95% CI = 1.79-2.31), but not to attend sporting events (OR = 1.47, 95% CI = .94-2.31). These results highlight the possible role of countries' gender inequality while supporting the spectator lek hypothesis.
Group music performance causes elevated pain thresholds and social bonding in small and large groups of singers Daniel Weinstein, Jacques Launay, Eiluned Pearce, Robin I.M. Dunbar, Lauren Stewart (2015) Evolution & Human Behavior
Over our evolutionary history, humans have faced the problem of how to create and maintain social bonds in progressively larger groups compared to those of our primate ancestors. Evidence from historical and anthropological records suggests that group music-making might act as a mechanism by which this large-scale social bonding could occur. While previous research has shown effects of music making on social bonds in small group contexts, the question of whether this effect ‘scales up’ to larger groups is particularly important when considering the potential role of music for large-scale social bonding. The current study recruited individuals from a community choir that met in both small (n = 20 – 80) and large (a ‘megachoir’ combining individuals from the smaller subchoirs n = 232) group contexts. Participants gave self-report measures (via a survey) of social bonding and had pain threshold measurements taken (as a proxy for endorphin release) before and after 90 minutes of singing. Results showed that feelings of inclusion, connectivity, positive affect, and measures of endorphin release all increased across singing rehearsals and that the influence of group singing was comparable for pain thresholds in the large versus small group context. Levels of social closeness were found to be greater at pre- and post-levels for the small choir condition. However, the large choir condition experienced a greater change in social closeness as compared to the small condition. The finding that singing together fosters social closeness – even in large contexts where individuals are not known to each other – is consistent with evolutionary accounts that emphasize the role of music in social bonding, particularly in the context of creating larger cohesive groups than other primates are able to manage.
James Y. Zou, Danny S. Park, Esteban G. Burchard, Dara G. Torgerson, Maria Pino-Yanes, Yun S. Song,
Sriram Sankararaman, Eran Halperin, and Noah Zaitlen; (2015)
Nonrandom mating in human populations has important implications
for genetics and medicine as well as for economics and sociology.
In this study, we performed an integrative analysis of a large cohort of
Mexican and Puerto Rican couples using detailed socioeconomic
attributes and genotypes. We found that in ethnically homogeneous
Latino communities, partners are significantly more similar in their
genomic ancestries than expected by chance. Consistent with this, we
also found that partners are more closely related—equivalent to between
third and fourth cousins in Mexicans and Puerto Ricans—than
matched random male–female pairs. Our analysis showed that this
genomic ancestry similarity cannot be explained by the standard socioeconomic
measurables alone. Strikingly, the assortment of genomic
ancestry in couples was consistently stronger than even the assortment
of education. We found enriched correlation of partners’ genotypes
at genes known to be involved in facial development. We
replicated our results across multiple geographic locations. We discuss
the implications of assortment and assortment-specific loci on disease
dynamics and disease mapping methods in Latinos.
Holly B. Shakya, Nicholas A. Christakis and James H. Fowler (2015)
We explored whether individuals' comparison of themselves to their social contacts, specifically feeling fitter or thinner than friends, is a significant predictor of three weight-loss behaviors (dieting, reducing alcohol, exercising).
We used a longitudinal survey of a national sample of Americans (N = 20,373) to measure respondents' personal social networks and their self-comparisons to their social contacts at two annual waves.
Participants who felt thinner than friends in Wave 1 had 1.16 lower odds of dieting in Wave 2. Those who felt fitter than friends in Wave 1 had 1.10 times higher odds of reducing alcohol and 1.18 times higher odds of exercising in Wave 2. We found that 20% of the relationship between feeling thin at baseline and subsequent dieting may be because feeling heavier than friends makes one want to lose weight. This same dynamic accounts for 25% of the relationship between feeling fit and dieting and 12% of the relationship between feeling thin and reducing alcohol.
These results suggest that normative self-comparison with important others is a potentially salient determinant of obesity-related health behavior and appears to work differently depending upon the behavior. Interventions may benefit from exploiting social comparisons in targeted ways.
Over the past few decades, mainstream health experts have universally recommended aerobic exercise as a uniquely health-promoting activity.
Yet now, Americans are fatter than ever. Aerobic exercise not only has a very poor record at fat loss, it might even cause weight gain.
Strength training - also known as weightlifting or resistance training - has much greater power to cause fat loss. What's more, since it builds muscle mass, strength training has huge advantages over aerobic exercise when it comes to improving health.
Greater muscle strength means less cancer and heart disease, besides smaller waist size and less body fat.
Aerobic exercise, while it can increase cardiovascular fitness, does next to nothing to combat two of the central maladies of aging: sarcopenia (loss of muscle) and osteoporosis.
Strength training robustly fights sarcopenia and osteoporosis, and can stop older adults from becoming frail and can keep them out of nursing homes.
Whether you're a young and healthy man, a middle-aged woman looking to lose fat, or an elderly person who wants to stay strong and independent, strength training has the most to offer of any exercise.
Everyone who exercises should add a strength training component to it. There's simply no other better way to fight obesity, diabetes, cancer, and frailty, and to instill self-confidence and get an attractive body.
Muscle Up shows why everyone should train for strength and why aerobic exercise is not optimal.
The book surveys the beneficial health effects of strength training, all of it supported by scientific research, with studies cited. You'll also learn how to start a strength training program.
There's also a chapter on strength training's cousin, high-intensity interval training (HIT), which can get you in superb physical condition in literally just minutes a week.
If you're not getting the results you want from your aerobic exercise, read Muscle Up and see why you should take up strength training. Or you could keep jogging or using the stair-stepper for a few more years and see how that works.
"children's development is the end of a much longer process that involves many complex decisions by parents, one of which is how many children they should have and how much love and care they should lavish on each. But even before they get to this stage, the parents must agree to choose each other as mates. It's probably fair to say that these are the two biggest decisions that we make in our lives".
Genetic specificity of face recognition
Nicholas G. Shakeshaft and Robert Plomin (2015)
Diverse cognitive abilities have typically been found to intercorrelate highly and to be strongly influenced by genetics. Recent twin studies have suggested that the ability to recognize human faces is an exception: it is similarly highly heritable, but largely uncorrelated with other abilities. However, assessing genetic relationships—the degree to which traits are influenced by the same genes—requires very large samples, which have not previously been available. This study, using data from more than 2,000 twins, shows for the first time, to our knowledge, that the genetic influences on face recognition are almost entirely unique. This finding provides strong support for the view that face recognition is “special” and may ultimately illuminate the nature of cognitive abilities in general.
Specific cognitive abilities in diverse domains are typically found to be highly heritable and substantially correlated with general cognitive ability (g), both phenotypically and genetically. Recent twin studies have found the ability to memorize and recognize faces to be an exception, being similarly heritable but phenotypically substantially uncorrelated both with g and with general object recognition. However, the genetic relationships between face recognition and other abilities (the extent to which they share a common genetic etiology) cannot be determined from phenotypic associations. In this, to our knowledge, first study of the genetic associations between face recognition and other domains, 2,000 18- and 19-year-old United Kingdom twins completed tests assessing their face recognition, object recognition, and general cognitive abilities. Results confirmed the substantial heritability of face recognition (61%), and multivariate genetic analyses found that most of this genetic influence is unique and not shared with other cognitive abilities.