Saturday, January 6, 2018

Many information structures generate correlated rather than mutually independent signals, like the news media. We provide experimental evidence that many people neglect the resulting double-counting problem in the updating process, so beliefs are too sensitive to the ubiquitous "telling and re-telling of stories"

Correlation Neglect in Belief Formation. Benjamin Enke, Florian Zimmermann. The Review of Economic Studies, rdx081, https://doi.org/10.1093/restud/rdx081

Abstract: Many information structures generate correlated rather than mutually independent signals, the news media being a prime example. This paper provides experimental evidence that many people neglect the resulting double-counting problem in the updating process. In consequence, beliefs are too sensitive to the ubiquitous "telling and re-telling of stories" and exhibit excessive swings. We identify substantial and systematic heterogeneity in the presence of the bias and investigate the underlying mechanisms. The evidence points to the paramount importance of complexity in combination with people's problems in identifying and thinking through the correlation. Even though most participants in principle have the computational skills that are necessary to develop rational beliefs, many approach the problem in a wrong way when the environment is moderately complex. Thus, experimentally nudging people's focus towards the correlation and the underlying independent signals has large effects on beliefs.

This man is superhuman, and very rarely lets his feelings color his economic judgement. In fact, it seems that this happened to him just once, and quickly retracted. Besides, he is so old-fashioned that he tries to admit and learn from his mistakes

This man is superhuman, and very rarely lets his feelings color his economic judgement. In fact, it seems that this happened to him just once, and quickly retracted. Besides, he is so old-fashioned that he tries to admit and learn from his mistakes:

Can the Economy Keep Calm and Carry On? Paul Krugman. The New York Times, Jan 01 2018, https://www.nytimes.com/2018/01/01/opinion/can-the-economy-keep-calm-and-carry-on.html
On election night 2016, I gave in temporarily to a temptation I warn others about: I let my political feelings distort my economic judgment. A very bad man had just won the Electoral College; and my first thought was that this would translate quickly into a bad economy. I quickly retracted the claim, and issued a mea culpa. (Being an old-fashioned guy, I try to admit and learn from my mistakes.)

What I should have clung to, despite my dismay, was the well-known proposition that in normal times the president has very little influence on macroeconomic developments — far less influence than the chair of the Federal Reserve.

[...]
 ---

        "Some have asked if there aren't conservative sites I read regularly. Well, no. I will read anything I've been informed about that's either interesting or revealing; but I don't know of any economics or politics sites on that side that regularly provide analysis or information I need to take seriously."--Paul Krugman, New York Times website, March 8, 2011, http://krugman.blogs.nytimes.com/2011/03/08/other-stuff-i-read/

        "I brought up the work of the legal scholar Cass Sunstein, now with the Obama administration, who has studied the radicalizing effects of ideological isolation--the idea, born from studies of three-judge panels, that if you are not in regular conversation with people who differ from you, you can become far more extreme. It is a very Obama idea, and I asked Krugman if he ever worried that he might succumb to that tendency. 'It could happen,' he says. 'But I work a lot from data; that's enough of an anchor. I have a good sense when a claim has gone too far.' "--Benjamin Wallace-Wells, New York magazine, April 24, 2011, http://nymag.com/print/?/news/politics/paul-krugman-2011-5/index5.html

 

Update: The Washington Post & Gavin Schmidt on Sept 2023 temps https://www.bipartisanalliance.com/2023/10/the-washington-post-gavin-schmidt-on.html

Investigation of brain structure in the 1-month infant – Girls and boys are different by then...

Investigation of brain structure in the 1-month infant. Douglas C. Dean III. Brain Structure and Function, https://link.springer.com/article/10.1007/s00429-017-1600-2

Abstract: The developing brain undergoes systematic changes that occur at successive stages of maturation. Deviations from the typical neurodevelopmental trajectory are hypothesized to underlie many early childhood disorders; thus, characterizing the earliest patterns of normative brain development is essential. Recent neuroimaging research provides insight into brain structure during late childhood and adolescence; however, few studies have examined the infant brain, particularly in infants under 3 months of age. Using high-resolution structural MRI, we measured subcortical gray and white matter brain volumes in a cohort (N = 143) of 1-month infants and examined characteristics of these volumetric measures throughout this early period of neurodevelopment. We show that brain volumes undergo age-related changes during the first month of life, with the corresponding patterns of regional asymmetry and sexual dimorphism. Specifically, males have larger total brain volume and volumes differ by sex in regionally specific brain regions, after correcting for total brain volume. Consistent with findings from studies of later childhood and adolescence, subcortical regions appear more rightward asymmetric. Neither sex differences nor regional asymmetries changed with gestation-corrected age. Our results complement a growing body of work investigating the earliest neurobiological changes associated with development and suggest that asymmetry and sexual dimorphism are present at birth.

How Hot Are They? Neural Correlates of Genital Arousal: An Infrared Thermographic and Functional Magnetic Resonance Imaging Study of Sexual Arousal in Men and Women

Parada M, GĂ©rard M, Larcher K, et al. How Hot Are They? Neural Correlates of Genital Arousal: An Infrared Thermographic and Functional Magnetic Resonance Imaging Study of Sexual Arousal in Men and Women. J Sex Med 2017;xx:xxx–xxx. https://doi.org/10.1016/j.jsxm.2017.12.006

Abstract

Background: The few studies that have examined the neural correlates of genital arousal have focused on men and are methodologically hard to compare.

Aim: To investigate the neural correlates of peripheral physiologic sexual arousal using identical methodology for men and women.

Methods: 2 groups (20 men, 20 women) viewed movie clips (erotic, humor) while genital temperature was continuously measured using infrared thermal imaging. Participants also continuously evaluated changes in their subjective arousal and answered discrete questions about liking the movies and wanting sexual stimulation. Brain activity, indicated by blood oxygen level-dependent (BOLD) response, was measured using functional magnetic resonance imaging.

Outcomes: BOLD responses, genital temperature, and subjective sexual arousal.

Results: BOLD activity in a number of brain regions was correlated with changes in genital temperature in men and women; however, activation in women appeared to be more extensive than in men, including the anterior and posterior cingulate cortex, right cerebellum, insula, frontal operculum, and paracingulate gyrus. Examination of the strength of the correlation between BOLD response and genital temperature showed that women had a stronger brain-genital relation compared with men in a number of regions. There were no brain regions in men with stronger brain-genital correlations than in women.

Clinical Translation: Our findings shed light on the neurophysiologic processes involved in genital arousal for men and women. Further research examining the specific brain regions that mediate our findings is necessary to pave the way for clinical application.

Strengths and Limitations: A strength of the study is the use of thermography, which allows for a direct comparison of the neural correlates of genital arousal in men and women. This study has the common limitations of most laboratory-based sexual arousal research, including sampling bias, lack of ecologic validity, and equipment limitations, and those common to neuroimaging research, including BOLD signal interpretation and neuroimaging analysis issues.

Conclusions: Our findings provide direct sex comparisons of the neural correlates of genital arousal in men and women and suggest that brain-genital correlations could be stronger in women.

Key Words: Genital Arousal; Functional Magnetic Resonance Imaging; Sexual Arousal; Gender Differences; Thermography

Sam Rosenfeld's The Polarizers: Modern political polarization was a deliberate project carried out by Democratic and Republican activists

The Polarizers: Postwar Architects of Our Partisan Era Hardcover. Sam Rosenfeld. December 28, 2017, https://www.amazon.com/Polarizers-Postwar-Architects-Our-Partisan/dp/022640725X

Even in this most partisan and dysfunctional of eras, we can all agree on one thing: Washington is broken. Politicians take increasingly inflexible and extreme positions, leading to gridlock, partisan warfare, and the sense that our seats of government are nothing but cesspools of hypocrisy, childishness, and waste. The shocking reality, though, is that modern polarization was a deliberate project carried out by Democratic and Republican activists.

In The Polarizers, Sam Rosenfeld details why bipartisanship was seen as a problem in the postwar period and how polarization was then cast as the solution. Republicans and Democrats feared that they were becoming too similar, and that a mushy consensus imperiled their agendas and even American democracy itself. Thus began a deliberate move to match ideology with party label—with the toxic results we now endure. Rosenfeld reveals the specific politicians, intellectuals, and operatives who worked together to heighten partisan discord, showing that our system today is not (solely) a product of gradual structural shifts but of deliberate actions motivated by specific agendas. Rosenfeld reveals that the story of Washington’s transformation is both significantly institutional and driven by grassroots influences on both the left and the right.

The Polarizers brilliantly challenges and overturns our conventional narrative about partisanship, but perhaps most importantly, it points us toward a new consensus: if we deliberately created today’s dysfunctional environment, we can deliberately change it.