Saturday, September 16, 2017

Myths and truths about the cellular composition of the human brain: A review of influential concepts

Myths and truths about the cellular composition of the human brain: A review of influential concepts. Christopher S.Bvon Bartheld. Journal of Chemical Neuroanatomy, https://doi.org/10.1016/j.jchemneu.2017.08.004

Highlights
•    The myth of a 10:1 glia-neuron ratio in human brains has been debunked.
•    The myth of one trillion glial cells in human brains has been debunked.
•    The number of cortical neurons does not decline significantly in normal aging.
•    All counting methods benefit from calibration and validation.
•    Proof is needed for altered cell numbers in neurological and psychiatric disorders.

Abstract: Over the last 50 years, quantitative methodology has made important contributions to our understanding of the cellular composition of the human brain. Not all of the concepts that emerged from quantitative studies have turned out to be true. Here, I examine the history and current status of some of the most influential notions. This includes claims of how many cells compose the human brain, and how different cell types contribute and in what ratios. Additional concepts entail whether we lose significant numbers of neurons with normal aging, whether chronic alcohol abuse contributes to cortical neuron loss, whether there are significant differences in the quantitative composition of cerebral cortex between male and female brains, whether superior intelligence in humans correlates with larger numbers of brain cells, and whether there are secular (generational) changes in neuron number. Do changes in cell number or changes in ratios of cell types accompany certain diseases, and should all counting methods, even the theoretically unbiased ones, be validated and calibrated? I here examine the origin and the current status of major influential concepts, and I review the evidence and arguments that have led to either confirmation or refutation of such concepts. I discuss the circumstances, assumptions and mindsets that perpetuated erroneous views, and the types of technological advances that have, in some cases, challenged longstanding ideas. I will acknowledge the roles of key proponents of influential concepts in the sometimes convoluted path towards recognition of the true cellular composition of the human brain.

Abbreviations: CNScentral nervous system
GNR glia-neuron ratio
IF isotropic fractionator

Individuals who follow and are followed by the people who correct them are significantly more likely to accept the correction than individuals confronted by strangers

Political Fact-Checking on Twitter: When Do Corrections Have an Effect? Drew Margolin, Aniko Hannak and Ingmar Weber. Political Communication, http://dx.doi.org/10.1080/10584609.2017.1334018

Abstract: Research suggests that fact checking corrections have only a limited impact on the spread of false rumors. However, research has not considered that fact-checking may be socially contingent, meaning there are social contexts in which truth may be more or less preferred. In particular, we argue that strong social connections between fact-checkers and rumor spreaders encourage the latter to prefer sharing accurate information, making them more likely to accept corrections. We test this argument on real corrections made on Twitter between January 2012 and April 2014. As hypothesized, we find that individuals who follow and are followed by the people who correct them are significantly more likely to accept the correction than individuals confronted by strangers. We then replicate our findings on new data drawn from November 2015 to February, 2016. These findings suggest that the underlying social structure is an important factor in the correction of misinformation.

Keywords: accountability, fact-checking, misinformation, rumor, social networks

Land plants have regulated their stomatal conductance to allow their intrinsic water use efficiency to increase in nearly constant proportion to the rise in atmospheric [CO2]

Atmospheric evidence for a global secular increase in carbon isotopic discrimination of land photosynthesis. Ralph F. Keeling et al. Proceedings of the National Academy of Sciences, http://m.pnas.org/content/early/2017/09/05/1619240114

Significance: Climate change and rising CO2 are altering the behavior of land plants in ways that influence how much biomass they produce relative to how much water they need for growth. This study shows that it is possible to detect changes occurring in plants using long-term measurements of the isotopic composition of atmospheric CO2. These measurements imply that plants have globally increased their water use efficiency at the leaf level in proportion to the rise in atmospheric CO2 over the past few decades. While the full implications remain to be explored, the results help to quantify the extent to which the biosphere has become less constrained by water stress globally.

Abstract: A decrease in the 13C/12C ratio of atmospheric CO2 has been documented by direct observations since 1978 and from ice core measurements since the industrial revolution. This decrease, known as the 13C-Suess effect, is driven primarily by the input of fossil fuel-derived CO2 but is also sensitive to land and ocean carbon cycling and uptake. Using updated records, we show that no plausible combination of sources and sinks of CO2 from fossil fuel, land, and oceans can explain the observed 13C-Suess effect unless an increase has occurred in the 13C/12C isotopic discrimination of land photosynthesis. A trend toward greater discrimination under higher CO2 levels is broadly consistent with tree ring studies over the past century, with field and chamber experiments, and with geological records of C3 plants at times of altered atmospheric CO2, but increasing discrimination has not previously been included in studies of long-term atmospheric 13C/12C measurements. We further show that the inferred discrimination increase of 0.014 ± 0.007‰ ppm−1 is largely explained by photorespiratory and mesophyll effects. This result implies that, at the global scale, land plants have regulated their stomatal conductance so as to allow the CO2 partial pressure within stomatal cavities and their intrinsic water use efficiency to increase in nearly constant proportion to the rise in atmospheric CO2 concentration.

A semantic space analysis of how presidential candidates and their supporters represent abstract political concepts differently

Speaking two "Languages" in America: A semantic space analysis of how presidential candidates and their supporters represent abstract political concepts differently. Ping Li, Benjamin Schloss and  Jake Follmer. Behavior Research Methods, https://link.springer.com/article/10.3758%2Fs13428-017-0931-5

Abstract: In this article we report a computational semantic analysis of the presidential candidates' speeches in the two major political parties in the USA. In Study One, we modeled the political semantic spaces as a function of party, candidate, and time of election, and findings revealed patterns of differences in the semantic representation of key political concepts and the changing landscapes in which the presidential candidates align or misalign with their parties in terms of the representation and organization of politically central concepts. Our models further showed that the 2016 US presidential nominees had distinct conceptual representations from those of previous election years, and these patterns did not necessarily align with their respective political parties' average representation of the key political concepts. In Study Two, structural equation modeling demonstrated that reported political engagement among voters differentially predicted reported likelihoods of voting for Clinton versus Trump in the 2016 presidential election. Study Three indicated that Republicans and Democrats showed distinct, systematic word association patterns for the same concepts/terms, which could be reliably distinguished using machine learning methods. These studies suggest that given an individual's political beliefs, we can make reliable predictions about how they understand words, and given how an individual understands those same words, we can also predict an individual's political beliefs. Our study provides a bridge between semantic space models and abstract representations of political concepts on the one hand, and the representations of political concepts and citizens' voting behavior on the other.

Attitudes toward science seem to become ever more polarized

Attitudes Towards Science. Bastiaan T. Rutjens et al. Advances in Experimental Social Psychology, https://doi.org/10.1016/bs.aesp.2017.08.001

Abstract: As science continues to progress, attitudes toward science seem to become ever more polarized. Whereas some put their faith in science, others routinely reject and dismiss scientific evidence. This chapter provides an integration of recent research on how people evaluate science. We organize our chapter along three research topics that are most relevant to this goal: ideology, motivation, and morality. We review the relations of political and religious ideologies to science attitudes, discuss the psychological functions and motivational underpinnings of belief in science, and describe work looking at the role of morality when evaluating science and scientists. In the final part of the chapter, we apply what we know about science evaluations to the current crisis of faith in science and the open science movement. Here, we also take into account the increased accessibility and popularization of science and the (perceived) relations between science and industry.

Keywords: Science; Belief in science; Antiscience; Motivation; Ideology; Religion; Morality; Control; Order; Existential meaning; Popularization of science; Open science

Tax compliance is greater for women than men, but men are more willing to contribute to public goods

The Role of Gender in the Provision of Public Goods through Tax Compliance. David M. Bruner, John D'Attoma, Sven Steinmo. Journal of Behavioral and Experimental Economics, https://doi.org/10.1016/j.socec.2017.09.001

Highlights
•    The results of a large scale laboratory tax compliance experiment conducted in the U.S., the U.K., Sweden, and Italy with nearly 5000 subjects are reported.
•    We find significant evidence of gender differences in tax compliance and the willingness to contribute to public goods.
•    We find robust evidence that tax compliance is greater for women than men.
•    We also find evidence that men are more willing to contribute to public goods.
•    Overall, the compliance effect dominates the free-riding effect for the parameters in the experiment such that women bear a greater burden of the provision of the public good.

Abstract: The existing experimental literature suggests women are more compliant than men when paying taxes but may free ride more when contributing to public goods. It is unclear which effect dominates when paying for public goods through taxation. Experiments conducted in three European countries and the U.S. are used to investigate this issue. The results suggest that women bear a greater burden of the provision of public goods for the parameters in the experiment. The results indicate the gender gap in compliance is due to differences in both the extensive and intensive margins.

Keywords: Individual income tax; Public goods; Gender; Experiments
JEL codes:     H2; H26; C91

My comment: As if it were some kind of compensation, women hide less from taxation and smaller amounts than men, but men are more willing to contribute more if the benefits for all increase.

Friday, September 15, 2017

People believe that future others' preferences and beliefs will change to align with their own

The Belief in a Favorable Future. Todd Rogers, Don Moore and Michael Norton. Psychological Science, Volume 28, issue 9, page(s): 1290-1301, https://doi.org/10.1177/0956797617706706

Abstract: ***People believe that future others' preferences and beliefs will change to align with their own***. People holding a particular view (e.g., support of President Trump) are more likely to believe that future others will share their view than to believe that future others will have an opposing view (e.g., opposition to President Trump). ***Six studies demonstrated this belief in a favorable future (BFF) for political views, scientific beliefs, and entertainment and product preferences***. BFF is greater in magnitude than the tendency to believe that current others share one's views (false-consensus effect), arises across cultures, is distinct from general optimism, is strongest when people perceive their views as being objective rather than subjective, and can affect (but is distinct from) beliefs about favorable future policy changes. A lab experiment involving monetary bets on the future popularity of politicians and a field experiment involving political donations (N = 660,542) demonstrated that BFF can influence people's behavior today.

Authoritarianism and Affective Polarization: A New View on the Origins of Partisan Extremism

Authoritarianism and Affective Polarization: A New View on the Origins of Partisan Extremism. Matthew Luttig. Public Opinion Quarterly, nfx023, https://doi.org/10.1093/poq/nfx023

Abstract: What drives affective polarization in American politics? One common argument is that Democrats and Republicans are deeply polarized today because they are psychologically different - motivated by diametrically opposed and clashing worldviews. This paper argues that the same psychological motivation - authoritarianism - is positively related to partisan extremism among both Republicans and Democrats. Across four studies, this paper shows that authoritarianism is associated with strong partisanship and heightened affective polarization among both Republicans and Democrats. Thus, strong Republicans and Democrats are psychologically similar, at least with respect to authoritarianism. As authoritarianism provides an indicator of underlying needs to belong, these findings support a view of mass polarization as nonsubstantive and group-centric, not driven by competing ideological values or clashing psychological worldviews.

Staggering SNAP benefits throughout the month leads to a 32 pct decrease in grocery store theft

SNAP Benefits and Crime: Evidence from Changing Disbursement Schedules. Jillian B. Carr and Analisa Packham. University of Miami, Oxford, OH., Department of Economics
Working Paper # - 2017-01. http://www.fsb.muohio.edu/fsb/ecopapers/prog/displayprof.php?id=packhaam

Abstract: Government transfer programs infuse a substantial amount of resources into the budgets of millions of low-income families each month. Under some states' aid disbursement schemes, there are extended periods of time within each month in which no recipients receive transfers, generally limiting the amount of resources in communities. In this paper, we study the effects of nutritional aid disbursement on crime, utilizing two main sources of variation: (i) a policy change in Illinois which substantially increased the number of SNAP distribution days, and (ii) an existing Indiana policy that issues SNAP benefits by last name. We find that ***staggering SNAP benefits throughout the month leads to a 32 percent decrease in grocery store theft and reduces monthly cyclicity in grocery store crimes***. Moreover, we find that the relationship between time since SNAP issuance and crime is nonlinear. Findings show that criminal behavior decreases in the second and third weeks following receipt, but increases in the last week of the benefit cycle, potentially due to resource constraints.

My comment: Petty crime is rational most of the time... If you get government money you commit less theft, probably due to the cost (jail time, fines). If you don't get the money it pays to enter into small theft, despite possible consequences.

Obviously, impulsivity is also an issue here. They control better their spending if the money is staggered, but if they get a lump sum every month, theft increases in the last week of that month...

Students who believed that their peers were more socially connected reported lower well-being and belonging

From Misperception to Social Connection: Correlates and Consequences of Overestimating Others’ Social Connectedness. Ashley V. Whillans et al. Personality and Social Psychology Bulletin, https://doi.org/10.1177/0146167217727496

Abstract: Two studies document the existence and correlates of a widespread social belief, wherein individuals who have recently moved to a new social environment see their peers as more socially connected than they themselves are. In Study 1, the prevalence of this belief was documented in a large sample of first-year students (N = 1,099). In Study 2, the prevalence of this social belief was replicated in a targeted sample of university students (N = 389). Study 2 also documented both positive and negative implications of this belief. Specifically, at any given time, students who believed that their peers were more socially connected reported lower well-being and belonging. Over time, however, the belief that one’s peers are moderately more socially connected than oneself was associated with more friendship formation.

Thursday, September 14, 2017

Backward planning led to greater motivation, higher goal expectancy, less time pressure and better goal-relevant performance

Relative Effects of Forward and Backward Planning on Goal Pursuit. Jooyoung Park, Fang-Chi Lu, and William M. Hedgcock. Psychological Science, https://doi.org/10.1177/0956797617715510

Abstract: Considerable research has shown that planning plays an important role in goal pursuit. But how does the way people plan affect goal pursuit? Research on this question is scarce. In the current research, we examined how planning the steps required for goal attainment in chronological order (i.e., forward planning) and reverse chronological order (i.e., backward planning) influences individuals’ motivation for and perceptions of goal pursuit. Compared with forward planning, backward planning not only led to greater motivation, higher goal expectancy, and less time pressure but also resulted in better goal-relevant performance. We further demonstrated that this motivational effect occurred because backward planning allowed people to think of tasks required to reach their goals more clearly, especially when goals were complex to plan. These findings suggest that the way people plan matters just as much as whether or not they plan.

Wind farms suppressed soil moisture and enhanced water stress

The Observed Impacts of Wind Farms on Local Vegetation Growth in Northern China. Bijian Tang et al.

Abstract: Wind farms (WFs) can affect the local climate, and local climate change may influence underlying vegetation. Some studies have shown that WFs affect certain aspects of the regional climate, such as temperature and rainfall. However, there is still no evidence to demonstrate whether WFs can affect local vegetation growth, a significant part of the overall assessment of WF effects. In this research, based on the moderate-resolution imaging spectroradiometer (MODIS) vegetation index, productivity and other remote-sensing data from 2003 to 2014, the effects of WFs in the Bashang area of Northern China on vegetation growth and productivity in the summer (June–August) were analyzed. The results showed that: (1) WFs had a significant inhibiting effect on vegetation growth, as demonstrated by decreases in the leaf area index (LAI), the enhanced vegetation index (EVI), and the normalized difference vegetation index (NDVI) of approximately 14.5%, 14.8%, and 8.9%, respectively, in the 2003–2014 summers. There was also an inhibiting effect of 8.9% on summer gross primary production (GPP) and 4.0% on annual net primary production (NPP) coupled with WFs; and (2) the major impact factors might be the changes in temperature and soil moisture: WFs suppressed soil moisture and enhanced water stress in the study area. This research provides significant observational evidence that WFs can inhibit the growth and productivity of the underlying vegetation.

Keywords: wind farm impact; vegetation decrease; satellite observations; GPP; land surface temperature; land use change

My comment: Despite knowing this and many other reasons, we keep supporting wind farms...

Wheat Agriculture Induce Bigger GDP, Which Yields Smaller Family Ties

Wheat Agriculture and Family Ties. James Ang & Per Fredriksson. European Economic Review, Volume 100, November 2017, Pages 236-256, https://doi.org/10.1016/j.euroecorev.2017.08.007

Abstract: Several recent contributions to the literature have suggested that the strength of family ties is related to various economic and social outcomes. For example, Alesina and Giuliano (2014) highlight that the strength of family ties is strongly correlated with lower GDP and lower quality of institutions. However, the forces shaping family ties remain relatively unexplored in the literature. This paper proposes and tests the hypothesis that the agricultural legacy of a country matters for shaping the strength of its family ties. Using data from the World Values Survey and the European Values Study, the results show that societies with a legacy in cultivating wheat tend to have weaker family ties. Analysis at the sub-national level (US data) and the country level corroborate these findings. The estimations allow for alternative hypotheses which propose that pathogen stress and climatic variation can potentially also give rise to the formation of family ties. The results suggest that the suitability of land for wheat production is the most influential factor in explaining the variation in the strength of family ties across societies and countries.

Extraversion and life satisfaction: A cross-cultural examination of student and nationally representative samples

Kim, H., Schimmack, U., Oishi, S. and Tsutsui, Y. (), Extraversion and life satisfaction: A cross-cultural examination of student and nationally representative samples. Journal of Personality. Accepted Author Manuscript. doi:10.1111/jopy.12339

Method: The current study examined student and nationally representative samples from Canada, US, UK, Germany and Japan (Study 1, N = 1,460; Study 2, N = 5,882; Study 3, N =18,683; Study 4, N = 13,443; Study 5, Japan N = 952 and US N = 891). The relationship between Extraversion and life satisfaction was examined using structural equation modeling by regressing life satisfaction on the Big Five traits.

Results: Extraversion was a unique predictor of life satisfaction in the North American student and nationally representative samples (Study 1, β = .232; Study 2, β = .225; Study 5, β = .217) but the effect size was weaker or absent in other non-North American samples (Germany, UK, and Japan).

Can Superstition Create a Self-Fulfilling Prophecy? School Outcomes of Dragon Children of China

Can Superstition Create a Self-Fulfilling Prophecy? School Outcomes of Dragon Children of China. Naci Mocan and Han Yu. NBER Working Paper, August 2017, http://www.nber.org/papers/w23709

Abstract: In Chinese culture those who are born in the year of the Dragon under the zodiac calendar are believed to be destined for good fortune and greatness, and parents prefer their kids to be born in a Dragon year. Using province level panel data we show that the number of marriages goes up during the two years preceding a Dragon year and that births jump up in a Dragon year. Using three recently collected micro data sets from China we show that those born in a Dragon year are more likely to have a college education, and that they obtain higher scores at the university entrance exam. Similarly, Chinese middle school students have higher test scores if they are born in a Dragon year. We show that these results are not because of family background, student cognitive ability, self-esteem or students’ expectations about their future. We find, however, that the “Dragon” effect on test scores is eliminated when we account for parents’ expectations about their children’s educational and professional success. We find that parents of Dragon children have higher expectations for their children in comparison to other parents, and that they invest more heavily in their children in terms of time and money. Even though neither the Dragon children nor their families are inherently different from other children and families, the belief in the prophecy of success and the ensuing investment become self-fulfilling.