Friday, January 15, 2021

Much of science, including public health research, focuses on means (averages); the purpose of the present paper is to reinforce the idea that variability matters just as well

Variability Matters. Maarten Jan Wensink, Linda Juel Ahrenfeldt and Sören Möller. Int. J. Environ. Res. Public Health 2021, 18(1), 157; December 28 2020. https://doi.org/10.3390/ijerph18010157

Abstract: Much of science, including public health research, focuses on means (averages). The purpose of the present paper is to reinforce the idea that variability matters just as well. At the hand of four examples, we highlight four classes of situations where the conclusion drawn on the basis of the mean alone is qualitatively altered when variability is also considered. We suggest that some of the more serendipitous results have their origin in variability.

Keywords: inequality; statistical inference; forecasting; lifespan; socioeconomic status; academic performance

6. Discussion

However witty, the accusation levelled against statisticians in the epigraph of this article is unfair. A statistician would always begin by listing some summary statistics of the data (the river, in this case), including variance, minimum and maximum values, and perhaps some quantiles. A statistician would also have some concern with the consequences of making a wrong decision: if these consequences are grave, such as drowning, a statistician would tolerate a smaller likelihood of a wrong decision than when consequences are trivial. As a result, no statistician would set out to wade confidently through a river based solely on information about its average depth.
Nevertheless, the oversimplistic approach of considering the mean alone, and not the distribution around it, is taken all too often. We have given four examples of situations where we needed to augment the information provided by the mean with information about variability in order to draw more informed conclusions. These examples illustrated four classes of situations: (1) if variability is different between groups, means alone give little insight into the share of people that reach a certain threshold and are hence selected into some group (say, high-achieving mathematicians, first example); (2) failing to account for variability gives wrong predictions of future trends (second example); (3) increasing variability implies that not all in a population capitalize on positive health trends to the same extent (third example); and (4) means without variability do not reveal the potential extent of public health issues (fourth example). A mean alone says little about the proportion of a population that crosses a threshold, while different subgroups of a population may follow different trends. This phenomenon also seems to be evident in spread of infectious diseases, most recently the Coronavirus Disease 2019 (COVID-19), where there is large heterogeneity in disease spreading [28].
There are limits to the amount of information that a single number can contain. From that perspective, it is unsurprising that we found situations where averages alone (single numbers) were insufficient to describe relevant aspects of the situation. This immediately begs the question whether a single number like the variance or standard deviation can contain all the relevant aspects of variability. Of course, if data are described sufficiently well by a two-parameter distribution, such as the normal distribution, two numbers say it all. However, in more complex situations, we may need more. Just like an average may not always suffice, descriptions of variability in a single number may be insufficient as well depending on the question we are trying to answer. We then need to complement this information with more numbers, for example skew, which help determine which part of a population crosses a threshold, or which part of a population experience increases in life expectancy.
Piketty [2] finds the Gini coefficient (a single number between 0 and 1) insufficient to describe economic inequalities and their evolution, and instead resorts to quantiles, such as the proportion of the overall wealth possessed by the poorest half of the population, the upper 10%, the upper 5%, the upper 1%, or indeed the upper 0.1% or even 0.01%. Depending on the kind of inequality and the period that he studies, four or five of such quantiles are deemed sufficient to grasp the main elements of economic inequality and its evolution. In their approach of forecasting statistical moments of the age-at-death distribution, Pascariu et al. [29] found that using seven statistical moments tends to strike a good balance between simplicity and computational tractability. Standard statistical courses often teach the first four moments (mean, variance, skew, kurtosis), all of which can be explained intelligibly with pictures, which becomes increasingly difficult for higher moments. Variability, then, is multidimensional as well.
When an inequality is detected, the level of inequality determines whether intervention is indicated, and how. For example, the insurance element of pension systems implies that some people will accumulate more pension payments than others. Indeed, the guarantee of a monthly income is precisely the point of pension systems, so inequality in the total amount of pension received is not necessarily problematic. An issue may arise when certain subgroups can systematically expect to receive a higher pension payout for every Euro they pay into the pension system. This is a matter of some concern, as pension systems often redistribute from poor to rich. Life expectancy of the rich is higher, while in-payments tend to be proportional to monthly benefits. Thus, for every Euro paid in, the rich and educated can expect to receive much more pension than the poor and uneducated, which raises questions about fairness [30].
In the same vein, consider a simple model where every human consists of the same number of cells that are all equally prone to become malignant due to genetic mutations that all occur at the same rate [31]. In such a model, there are no differences between humans at age 0. Yet the age at which cancer occurs, or indeed whether cancer occurs at all before death by competing causes [32], tends to be greatly distinct. Here we have inequality in consequences without any inequality whatsoever in baseline conditions. Yet, we wish to address them, so we should do so as inequality in the outcome emerges. Notice how chances are even at birth, but we still feel we should mend inequality in the outcome.

Discrimination was positively associated with anxiety and negative affect, operationalized by a common latent factor; anxiety and related disorders are not a result of common genetic liability alone

Discrimination and anxiety: Using multiple polygenic scores to control for genetic liability. Adolfo G. Cuevas, Frank D. Mann, David R. Williams, and Robert F. Krueger. Proceedings of the National Academy of Sciences, January 5, 2021 118 (1) e2017224118; https://doi.org/10.1073/pnas.2017224118

Significance: Genetic factors can concurrently influence perceptions of threatening and stressful events, like discriminatory experiences, and increase liability for anxiety and negative affect. The question has remained unsettled as to whether genetic susceptibility to anxiety and negative affect confounds the relationship between discrimination exposure and these phenotypes. In a national probability sample of noninstitutionalized, English-speaking respondents (n = 1,146), we found that discrimination was positively associated with anxiety and negative affect, operationalized by a common latent factor, even after accounting for genetic confounds. These findings suggest that discrimination is a risk factor for anxiety and related disorders rather than a result of common genetic liability alone. Reducing exposure to discrimination has the potential to improve mental health at the population level.

Abstract: An established body of research indicates that discrimination is associated with increased symptoms of anxiety and negative affect. However, the association cannot be interpreted unambiguously as an exposure effect because a common set of genetic factors can simultaneously contribute to increased liability for symptoms of anxiety, negative affect, and the perception of discrimination. The present study elucidates the association between discrimination and anxiety/negative affect by implementing strict genetic controls in a large sample of adults. We used data from the biomarker project of the Study of Midlife Development in the United States (MIDUS), a national probability sample of noninstitutionalized, English-speaking respondents aged 25 to 74 y. Participants who consented to provide genetic data were biologically unrelated and of European ancestry as determined by genotype principal components analysis (n = 1,146). A single structural regression model was fit to the data with three measures of discrimination specified to load onto a latent factor and six measures of anxiety and negative affect specified to load onto a second latent factor. After accounting for potential genetic confounds—polygenic scores for anxiety, depression, and neuroticism and the first five genetic principal components—greater discrimination was associated with greater anxiety/negative affect (β = 0.53, SE = 0.04, P < 0.001). Findings suggest that measures of perceived discrimination should be considered environmental risk factors for anxiety/negative affect rather than indices of genetic liability for anxiety, depression, or neuroticism. Clinical interventions and prevention measures should focus on ways to mitigate the impact of discrimination to improve mental health at the population level.

Keywords: discriminationanxietynegative affectinternalizingpolygenic scores

The Serpentine Illusion: A Visual Motion Illusion Induced by Phase-Shifted Line Gratings

The Serpentine Illusion: A Visual Motion Illusion Induced by Phase-Shifted Line Gratings. Junxiang Luo et al. Front. Neurosci., December 7 2020. https://doi.org/10.3389/fnins.2020.612153

In a pattern of horizontal lines containing ± 45° zigzagging phase-shifted strips, vivid illusory motion is perceived when the pattern is translated up or down at a moderate speed. Two forms of illusory motion are seen: [i] a motion “racing” along the diagonal interface between the strips and [ii] lateral (sideways) motion of the strip sections. We found the relative salience of these two illusory motions to be strongly influenced by the vertical spacing and length of the line gratings, and the period length of the zigzag strips. Both illusory motions are abolished when the abutting strips are interleaved, separated by a gap or when a real line is superimposed at the interface. Illusory motion is also severely weakened when equiluminant colored grating lines are used. Illusory motion perception is fully restored at < 20% luminance contrast. Using adaptation, we find that line-ends alone are insufficient for illusory motion perception, and that both physical carrier motion and line orientation are required. We finally test a classical spatiotemporal energy model of V1 cells that exhibit direction tuning changes that are consistent with the direction of illusory motion. Taking this data together, we constructed a new visual illusion and surmise its origin to interactions of spatial and temporal energy of the lines and line-ends preferentially driving the magnocellular pathway.

General Discussion

In this paper, we describe a visual motion illusion, which we have called the Serpentine Illusion. It is elicited by a pattern of phase-shifted grating strips, abutting each other along a zigzagging interface. When the stimulus pattern is moved up or down, the intersections formed by the offset line gratings are seen to move in an undulating snake-like fashion. In addition to this motion along the diagonals, lateral motion of the sections is also seen. The strength of both illusory motions depends on the stimulus parameters. The illusion is luminance-contrast dependent, suggesting that magnocellular pathway signals have a predominant impact on the Serpentine Illusion. Results from selective adaptation show that both line gratings and physical motion are necessary for the full perception of the illusion, and modeling suggests the illusory motion can partly be explained by linear spatiotemporal receptive fields of motion sensitive V1 cells.

Visual Features Contributing to the Serpentine Illusion

We used an adaptation paradigm to test the contributions of orientation and motion mechanisms. We used moving and flashed grating-lines or grating-endpoints, and random dots, to adapt out the orientation, motion and end-stopping signals driven by the illusion inducing pattern. According to Figure 10, it was the moving line gratings that had the largest effect of weakening the perception of the Serpentine Illusion. To further test the contribution of line gratings for inducing the illusory motions, we introduced a pattern in which the line gratings of the original pattern were occluded by zigzag masks of varying thickness (Supplementary Figure 6). We found that illusory motion was abolished in the pattern with only endpoints visible (Supplementary Figure 6A), and only slightly restored when 1/2 or 1/3 of the grating lines were masked (Supplementary Figures 6B,C); illusory motion was weakened even with a very thin occluding mask (Supplementary Figure 6D). These observations suggest that continuous line gratings are crucial for the generation of both diagonal and lateral illusory motions.

Differences and Similarities Between Lateral and Diagonal Motion

Diagonal motion occurs primarily when the local contrast differences driven by the endpoints follow each other at close range (i.e., high density). This is the case when the line gratings are narrowly spaced, when the distance between the end points of a line is long and when the period length of the zigzags is short. This will make a grating strip look like an undulating column. On the other hand, lateral motion is favored by low density chains of end points as found with widely spaced line gratings, short horizontal distances between pairs of end points, and a long period of zigzags; these features favor a percept of horizontally arranged rows of end points moving sideward together. Apart from the parameters tested in Experiment 2, we further varied the angle of the zigzagging abutting interface. When the angle is changed to ± 30°, illusory motion along the diagonals predominates (Supplementary Figure 7A), whereas when the angle is changed to ± 60°, strong lateral motion is perceived (Supplementary Figure 7B). In the former case, the zigzags emphasize the vertical columnar structure, whereas at more acute angles the columns are less salient and the horizontal structure predominates. These parametric conditions for seeing diagonal and lateral illusory motion produce groupings that are consistent with the Gestalt principles of proximity and common fate. Whether these two illusory motion patterns drive the same or different underlying neural mechanisms remains unknown. The fact that either of the motion patterns can be almost eliminated when optimizing for the other condition (Supplementary Figures 24), suggests the neural mechanisms may be dissociable. Future studies will need to systemically explore the neural origins of both illusory motions using theoretical, psychophysical and physiological methods.

Illusory Motions Are Luminance-Contrast Dependent

Motion and color signals were classically thought to be encoded differentially (Ramachandran and Gregory, 1978Zeki, 1978Livingstone and Hubel, 1988). This parallel division receives some support from psychophysical studies in which chromatic gratings without luminance contrast can effectively weaken the ability of a subject to discriminate motion direction/speed (Cavanagh et al., 1984Troscianko and Fahle, 1988Cavanagh and Anstis, 1991Kooi and Devalois, 1992Mullen and Boulton, 1992abHenning and Derrington, 1994). Other studies, however, show that equiluminant color contrast can also provide weak cues for motion perception (Cavanagh and Favreau, 1985Saito et al., 1989Hawken et al., 1994Gegenfurtner and Hawken, 19951996a,bBurr et al., 1998Dougherty et al., 1999Lu et al., 1999Yoshizawa et al., 2000Willis and Anderson, 2002Cropper and Wuerger, 2005Burton and McKeefry, 2007). Cortical areas like MT (Saito et al., 1989Seidemann et al., 1999Thiele et al., 1999Wandell et al., 1999Barberini et al., 2005) and V3A (McKeefry et al., 2010) are able to encode motion signals derived from chromatically defined stimuli. In addition it is well known that area V4 encodes motion information and contains mixed parvocellular and magnocellular inputs (Desimone and Schein, 1987Mountcastle et al., 1987Ferrera and Maunsell, 2005Tolias et al., 2005Mysore et al., 2008An et al., 2012Li et al., 2013Yin et al., 2015Birman and Gardner, 2018). This physiological and anatomical data is consistent with the psychophysical data suggesting physical motion signals are processed through mixed pathways (Willis and Anderson, 2002Takeuchi et al., 2003McKeefry and Burton, 2009). Although the exact balance of interactions across form, color and motion signaling circuits is still a matter of some debate, there is nevertheless psychophysical evidence showing that motion illusions are minimized when presented under chromatic equiluminant conditions (Khang and Essock, 1997Hamburger, 2012).

The original Serpentine Illusion stimulus pattern has high luminance contrast between line gratings and background. When we reduced the contrast to physical equiluminance, illusory motion was greatly weakened (Figure 7). This suggests that luminance contrast is an important factor in generating the Serpentine Illusion, an observation consistent with several other motion illusions, which are found to be luminance-contrast dependent (Hamburger, 2012). Examples include the Pinna-Brelstaff illusion (Pinna and Brelstaff, 2000), the Rotating Snakes illusion (Kitaoka and Ashida, 2003), the Rotating-Tilted-Lines illusion (Gori and Hamburger, 2006), the Boogie-Woogie illusion (Cavanagh and Anstis, 2002), and the Dotted Lines illusion (Ito et al., 2009). This indicates that unlike physical motion, illusory motions in the Serpentine and other motion illusions are largely mediated by the magnocellular pathway. Additionally, previous psychophysical studies found that subjects underestimate the speed of moving gratings with relatively low luminance contrast (Campbell and Maffei, 1981Thompson, 1982Stone and Thompson, 1992Blakemore and Snowden, 1999Johnston et al., 1999Anstis, 2003). Analogously, the saliency of illusory motion can also be controlled through changing the strength of luminance contrast in the physical stimulus (Cavanagh and Anstis, 2002Anstis, 2004Backus and Oruc, 2005Howe et al., 2006Hamburger, 2012). It has been hypothesized that a moderate luminance contrast is the main factor in generating some motion illusions (Foster and Altschuler, 2001Cavanagh and Anstis, 2002Conway et al., 2005Ito et al., 2009Hamburger, 2012). However, for the Serpentine Illusion, only the extreme low luminance contrast (10% in Figure 8) can reduce the strength of the perceptual illusory motions.

The observations in Experiment 2 point toward a role for local contrast differences between the abutting line endings. Each pair of juxtaposed, phase-shifted line ends produces a dark patch that stands out when the stimulus pattern is moved up or down. One possible explanation of the illusory motion seen is due to the larger contrast of the dark patch relative to the grating strips. It is known that high-contrast gratings appear to move faster than low-contrast gratings (Thompson, 1982Stone and Thompson, 1992) and this might explain the faster rate at which the dark patches are seen to be moving relative to the flanking line gratings.

Alternatives to the Energy Model

Without directly recording from the nervous system, theoretical models are one of the best ways to infer neural mechanisms that underlie visual perceptual phenomenon. Here, we used the classical motion energy model (Adelson and Bergen, 1985) to show that primary visual cortex neurons respond with directional biases consistent with perception to the illusory motions in Serpentine Illusion stimuli. The motion energy model is a simplified linear summation model (Baker and Issa, 2005Mante and Carandini, 2005), best at predicting response properties in the earliest motion processing stages (Reid et al., 1987Carandini et al., 1997). Complex cells in primary visual cortex and neurons in downstream visual areas like MT and MST have more non-linear response properties (Emerson et al., 1992Simoncelli and Heeger, 1998Pack et al., 2006), and they contribute significantly to the neural representation and perception of illusory motions (Luo et al., 2019). Future studies should explore compare both linear and non-linear coding components and hierarchical population responses (mirroring the hierarchical spatiotemporal integration of motion information), as these may better predict the cortical responses to Serpentine and other illusory motion patterns.

Similarities and Differences Between Serpentine and Other Visual Illusions

The diagonal illusory motion along the zigzagging contour of the interface is reminiscent of the apparent motion in other two well-known motion illusions: the Boogie-Woogie illusion (Cavanagh and Anstis, 2002) and the dotted lines illusion (Ito et al., 2009). The Boogie-Woogie illusion is constructed by a grid of horizontal and vertical bars made up from alternating dark and bright squares placed on a gray background. When this grid is moved diagonally from the lower left to the upper right, the small squares making up the bars appear to “race” up the verticals and to the right along the horizontals. The authors attribute their illusion to different strengths of the motion signals elicited by the vertical and horizontal bars. Apparent upward motion resulting from the alternating light and dark edges of the squares moving “along” the bar (first-order motion) is said to constitute a more efficient motion signal than the “across” motion by the textured edge of the horizontal bar which therefore would appear to move more slowly and be overtaken by the vertically moving squares. The dotted lines illusion contains obliquely aligned white and black dots on a median gray background. Horizontal movement of the patten produce relative motion along the row of dots. The authors suggest that illusory motion is produced by the stronger luminance contrast between adjacent dots along the length of the line, compared to with the luminance difference between dotted lines and background.

Interestingly, another illusory motion effect can be perceived when the Serpentine Illusion picture is moved horizontally along the abutting line gratings (or by tracking the cursor as it moves leftward or rightward). The tilted zigzag illusory contours appears to swell out- or inward to each other. Such illusory motions are inconsistent with the aperture effect (Nakayama and Silverman, 1988), and appear related to the dotted-line illusion. Despite similarities, the lateral motion is not observed in either Boogie-Woogie illusion or dotted lines illusion. Moreover, the boogie-woogie illusion elicits the strongest motion at low contrast while the Serpentine Illusion becomes invisible at low contrast. Compared with the Boogie-Woogie and dotted lines illusion, the Serpentine Illusion does not contain luminance contrast along line gratings. Nevertheless, we cannot rule out the possibility that these three illusions may share similar underlying coding mechanisms, since luminance contrast is critical for producing illusory motion in all three patterns, and under equiluminant conditions, illusory motion is largely eliminated in all three patterns. Further psychophysical and physiological experiments are therefore needed to reveal the neuronal mechanisms underlying the Serpentine Illusion. 

Integrated information as a possible basis for plant consciousness: Surgical interventions suggest the shoot, root and cambial meristems are candidates for regions of integrated information

Integrated information as a possible basis for plant consciousness. Paco Calvo, František Baluška, AnthonyTrewavas. Biochemical and Biophysical Research Communications, October 17 2020. https://doi.org/10.1016/j.bbrc.2020.10.022

Highlights

• Integrated information constitutes a basis for plant awareness.

• A bottom-up biological view looks at the potential origins of consciousness to understand better its biological function.

• Surgical interventions suggest the shoot, root and cambial meristems are candidates for regions of integrated information.

• Plants retain a conscious capability, although the extent and size of the capability remains to be determined.

Abstract: It is commonly assumed that plants do not possess consciousness. Since the criterion for this assumption is usually human consciousness this assumption represents a top down attitude. It is obvious that plants are not animals and using animal criteria of consciousness will lead to its rejection in plants. However using a bottom up evolutionary approach and a leading theory of consciousness, Integrated Information Theory, we report that we find evidence that indicates that plant meristems act in a conscious fashion although probably at the level of minimal consciousness. Since many plants contain multiple meristems these observations highlight a very different evolutionary approach to consciousness in biological organisms.

Keywords: Plant consciousnessAwarenessIntegrated information theory (IIT)MeristemsBioelectrical fieldsSelection


What Caring for My Aging Parents Taught Me That Medical Education Did Not

What Caring for My Aging Parents Taught Me That Medical Education Did Not. David I. Rappaport. JAMA Neurol. 2021;78(1):7-8. Nov 23 2020, doi:10.1001/jamaneurol.2020.4454

As many children are, I was convinced that my parents would never truly get old. In their 50s and 60s, they were active, vibrant, and independent. Their many years of thriftiness had left them a solid financial situation, which my father maintained in exquisitely detailed Microsoft Excel spreadsheets. My mother, a master organizer, deftly planned everything, from our family’s international move to her weekly mahjong games. They managed 2 homes: 1 in the Northeast US and 1 in Florida. They frequently traveled with friends and relatives, sometimes not sharing details with their adult children until we received emailed photographs afterwards. My mother volunteered at her local children’s hospital—my place of employment—with enthusiasm for almost 20 years [...]

Slowly, however, things started to change. My parents seemed to have increasing difficulty staying organized. Instead of me calling them, they began calling me—at first weekly, then daily, and then multiple times per day. My father’s blood pressure was out of control, and he could not tell me what medications he was taking. My mother’s scoliosis, a problem since adolescence, now caused her to have significant difficulty walking. She looked thinner each time I saw her. Their physicians seemed not to be communicating well with each other. Finding their cell phones became a daily project.

[...]

The move from their home of 30 years was the next step. They simply could not manage the house. Once spotlessly clean, it was now increasingly cluttered with tchotchkes from circa 1993. The garden was overgrown, the dishes dirty. After work, I typically spent an hour every day helping organize, donate, and throw away their belongings, so that we could put the house up for sale. Thankfully, the renovations went smoothly and the house sold quickly. Although not without drama, my parents moved to a retirement facility nearby.

[...]

So here goes, the what-I-wish-I-knew list about caring for my aging parents, medically and otherwise. If this essay helps even 1 person or 1 family, it will have been worth the effort.

If you have the feeling that something may be an issue for your aging parents, it is almost definitely an issue. Do not put off something because it is likely to resolve itself; it will likely get worse, not better. As a pediatrician, I find myself frequently recommending to many of my patients and their parents to monitor their current condition and let me know if things change or get worse. This is in general the wrong approach for aging parents. It is better to deal with a manageable issue now rather than a big problem in the future.

  • Make sure you know about all your parents’ financial accounts. Finding out that my parents’ credit cards were used fraudulently after they had long forgotten about them made detective work very difficult. Make a list of accounts and get online access to them as soon as you recognize that your parents are showing any signs of cognitive decline. Simplify their life (and yours) by closing unnecessary accounts. We decided that my parents should have 1 credit card and 1 bank account, both of which I have access to on my cellphone. I check them almost every day.
  • You (and they) may need emotional support from people you would not expect. If, several years ago, someone had asked me about the most important reasons to hire a financial planner, I would never have included emotional support as one of them. Now I would rank it near the top. Having someone who knew my parents before they started to decline is incredibly helpful as we make financial and other important decisions on their behalf. The fact that my parents trust their adviser so much is a tremendous help. The same is true for their realtor.
  • Advocate for your parents in the best way you can, but do not expect everything to be cut and dried. Try to attend medical appointments with them whenever possible. Make a list of their medications with photographs of the pills included. Talk to the physician directly and make sure they know you are a medical professional. Do not expect clinicians to communicate effectively with each other. Even with the best plans, not everything will go according to the textbook. For example, my father repeatedly refused to do the Mini-Mental State Examination (MMSE). “These tests are designed to elicit failure,” he declared, of course without any knowledge of anything about the test. An incredibly kind geriatrician did not want to stress him by forcing him to do it. We eventually decided to treat him with medication despite not having a formal test result. My mother, in contrast, tried to cheat by studying for the MMSE the night before.
  • Use technology to help you (and them). Although my parents struggle with technology, that does not mean it cannot help them. I do not have any financial stake in any particular technology company, but there are several that we have found extremely useful. Medminder (www.medminder.com) is a company that offers smart pillboxes that reminds my father when to take his medications and alerts me via telephone, email, or text message if he has not yet taken the medication. Pillpack (www.pillpack.com) is a pharmacy service that packages the medications by day and time so that loading pillboxes is much easier. Tile (www.thetileapp.com) offers the ability to track multiple lost devices, such as cellphones and wallets. Gogograndparent (www.gogograndparent.com) allows senior citizens to use Lyft or Uber via a simple telephone call, rather than having to navigate the app. (I thank my cousin, a social worker, for that one.)
  • Do not expect too much from the medical system. Physicians, even caring and dedicated ones, may be unwilling to have difficult or unpleasant conversations. Neither the ophthalmologist nor the primary care physician, both lovely people and good physicians, seemed willing to risk my mother’s irritation by telling her that she could not drive (although clearly this was unsafe). Instead, one suggested an independent driving assessment program (and my mother balked when told it cost several hundred dollars). Navigating the medical system, including issues associated with insurance and disposition, also will likely fall to you. Thankfully, my parents have not required considerable inpatient hospitalizations, but colleagues whose parents have required inpatient and rehabilitation stays indicate that fighting with Medicare for extra hospitalization days is de rigueur. Social workers and care coordinators can help, but the ultimate responsibility will be yours.
  • You must have the difficult conversations if the physicians will not. You may need to have difficult conversations with your parents, your siblings, your children, and others. Regarding medical professionals, if you can, consider having a conversation with your parents’ physician(s) before the visit, so they understand your perspective and are not surprised when you ask them about issues (such as driving) with a specific agenda. Some of the most difficult conversations I have had with my parents included issues involving comparisons between them and their friends of similar ages. My mother often asks, “Why can’t I drive if all my friends are driving?” “Everyone ages differently,” was my usual reply. (I also remind her that several of her friends have died.) “I may want to play basketball like Lebron James, but there’s really no comparison. Let’s focus on you.”
  • You may need to get them daily help. A supportive and trustworthy aide (or aides) can be a tremendous help. My parents now have aides daily; I can immediately tell by the tone of my mother’s voice when the aide has not arrived that day. Once you get a system established, everyone will be much more comfortable. Aides who drive can be a compromise for senior citizens who want to remain independent but cannot safely drive themselves.
  • Do not forget to keep some perspective and occasionally laugh. These issues are harder on your parents than they are on you. Obviously, they did not choose to have dementia or Parkinson disease. They will need some time to mourn their losses: physical strength, independence, friendships, and living life on their terms. Their stubbornness (I call it status stubbornosus) may be difficult now, but it has served them well in other aspects of their lives. When asked during the MMSE to list as many words that start with the letter f as she could, my mother promptly replied, “F***.” She and the geriatrician agreed it should count as a real word. “Can’t make this stuff up…” I texted my sister.


Individual donors prefer to support ideologically extreme candidates; relaxation of contribution limits from political action committees lead to the selection of more moderate legislators

Ideological Donors, Contribution Limits, and the Polarization of American Legislatures. Michael J. Barber. The Journal of Politics, Volume 78, Number 1, Jan 2021. https://www.journals.uchicago.edu/doi/abs/10.1086/683453

Abstract: This article demonstrates that limits on campaign contributions—which alter a candidate’s ability to raise money from certain types of donors—affect the ideologies of legislators in office. Using an original data set of campaign contribution limits in some US states over the last 20 years, I exploit variation across and within states over time to show that higher individual contributions lead to the selection of more polarized legislators, while higher limits on contributions from political action committees (PACs) lead to the selection of more moderate legislators. Individual donors prefer to support ideologically extreme candidates while access-seeking PACs tend to support more moderate candidates. Thus, institutional changes that limit the availability of money affect the types of candidates who would normally fund-raise from these two main sources of campaign funds. These results show that the connection between donors and candidates is an important part of the story of the polarization of American politics.


Thursday, January 14, 2021

Oxford guys think that, in 2030, Africa total electricity generation will more than double current levels, & fossil fuels will account for 62pct of all generated electricity; of 2,500 power plants, about half will be coal & gas

A machine-learning approach to predicting Africa’s electricity mix based on planned power plants and their chances of success. Galina Alova, Philipp A. Trotter & Alex Money. Nature Energy, Jan 11 2021. https://www.nature.com/articles/s41560-020-00755-9

Abstract: Energy scenarios, relying on wide-ranging assumptions about the future, do not always adequately reflect the lock-in risks caused by planned power-generation projects and the uncertainty around their chances of realization. In this study we built a machine-learning model that demonstrates high accuracy in predicting power-generation project failure and success using the largest dataset on historic and planned power plants available for Africa, combined with country-level characteristics. We found that the most relevant factors for successful commissioning of past projects are at plant level: capacity, fuel, ownership and connection type. We applied the trained model to predict the realization of the current project pipeline. Contrary to rapid transition scenarios, our results show that the share of non-hydro renewables in electricity generation is likely to remain below 10% in 2030, despite total generation more than doubling. These findings point to high carbon lock-in risks for Africa, unless a rapid decarbonization shock occurs leading to large-scale cancellation of the fossil fuel plants currently in the pipeline.


When news is repeatedly retold it undergoes a stylistic transformation (disagreeable personalization), wherein original facts are increasingly supplanted by opinions and interpretations, with a slant toward negativity

The Dynamics of Distortion: How Successive Summarization Alters the Retelling of News. Shiri Melumad, Robert Meyer, Yoon Duk Kim. Journal of Marketing Research, January 7, 2021. https://doi.org/10.1177/0022243720987147

Abstract: In this work we advance and test a theory of how news information evolves as it is successively retold by consumers. Drawing on data from almost 11,000 participants across ten experiments, we offer evidence that when news is repeatedly retold it undergoes a stylistic transformation termed disagreeable personalization, wherein original facts are increasingly supplanted by opinions and interpretations, with a slant toward negativity. Specifically, the central thesis of the work is that, when retellers believe that they are more (vs. less) knowledgeable than their recipient about the information they are relaying, they feel more compelled to provide guidance on its meaning, and to do so in a persuasive manner. This enhanced motivation to guide persuasively, in turn, leads retellers to not only select the subset of facts they deem most essential but, critically, to provide their interpretations and opinions on those facts, with negativity being used as a means of grabbing the audience’s attention. Implications of the work for prior research on retelling and consumer information diffusion are explored.

Keywords: word-of-mouth, information diffusion, retelling, social media, natural language processing


Most women do not want a career in STEM and nor do most men; why should the small fraction of women who do want such a career be the same size as the small fraction of men?

Men, women and STEM: Why the differences and what should be done? Steve Stewart-Williams, Lewis G Halsey. European Journal of Personality, January 13, 2021. https://doi.org/10.1177/0890207020962326

Abstract: It is a well-known and widely lamented fact that men outnumber women in a number of fields in STEM (science, technology, engineering and maths). The most commonly discussed explanations for the gender gaps are discrimination and socialization, and the most common policy prescriptions target those ostensible causes. However, a great deal of evidence in the behavioural sciences suggests that discrimination and socialization are only part of the story. The purpose of this paper is to highlight other aspects of the story: aspects that are commonly overlooked or downplayed. More precisely, the paper has two main aims. The first is to examine the evidence that factors other than workplace discrimination contribute to the gender gaps in STEM. These include relatively large average sex differences in career and lifestyle preferences, and relatively small average differences in cognitive aptitudes – some favouring males, others favouring females – which are associated with progressively larger differences the further above the average one looks. The second aim is to examine the evidence suggesting that these sex differences are not purely a product of social factors but also have a substantial biological (i.e. inherited) component. A more complete picture of the causes of the unequal sex ratios in STEM may productively inform policy discussions.

Keywords: discrimination, equality, gender, sex differences, STEM

Having looked at how our analysis of STEM gender gaps might inform the conversation about policy options, we should step back and ask another, more fundamental question: what should the ultimate goal of these policies be? Should we strive for a 50:50 sex ratio in every area where men currently dominate? Or should we strive instead simply to eliminate bias and equalize people’s opportunities, then let the cards fall where they may?14

If men and women were identical in their aspirations and aptitudes, these would quite possibly amount to the same thing: levelling the playing field would automatically result in a 50:50 sex ratio, or something close to it. However, given that men and women are not identical in their aspirations and aptitudes, we have no reason to expect gender parity, even under conditions of perfect fairness. On the contrary, the natural expectation would be that men and women would not be at parity, but rather that men would be more common in some fields, and women in others, as a result of their freely made choices. To the extent that this is the case, it becomes much more difficult to justify pursuing a 50:50 sex ratio in every field. Most women do not want a career in STEM and nor do most men. Why should the small fraction of women who do want such a career be the same size as the small fraction of men? To put it another way, as long as everyone has the opportunity to pursue a STEM career, and as long as the selection process is fair, why would it be important to get as many women as men into jobs that fewer women want?

The pursuit of happiness

One way to start tackling this question would be to observe that a 50:50 sex ratio in STEM is presumably not a good in itself, but is a good only in as much as that it increases human wellbeing. Importantly, though, to the degree that occupational disparities are a product of men and women acting on their own preferences and pursuing their own best interests, it is doubtful that forcing a 50:50 sex ratio would actually achieve this end.

To begin with, men and women could have different life outcomes, but still be happy with their lives. One longitudinal study found that, among two cohorts of individuals identified as academically gifted as children, men and women had somewhat different aspirations and took somewhat different paths, but ended up similarly happy with their careers, their relationships and their lives overall (Lubinski et al., 2014). In other words, even among those best positioned to achieve their life ambitions, occupational gender parity appears not to be necessary for happiness.

Not only might it not be necessary, but policies that artificially engineer gender parity – financial incentives and quotas, for instance – could potentially lower aggregate happiness. To the extent that these policies work, they necessarily mean that some people will be funnelled into occupations that are less in line with their tastes and talents. To get more women into university physics programmes, for instance, would require persuading at least some women to choose that option when they otherwise would not have done so. (At the same time, unless enrolment numbers were increased, it would also mean turning away some men who otherwise would have.) The women in question would presumably not come from the ranks of housewives or secretaries; more than likely they would be women who would otherwise have gone into other, equally prestigious fields, such as law or medicine. Is there any reason to think that these women would be happier doing physics? Given that people tend to choose careers they think will suit them best and be most satisfying for them, it seems plausible to think that, on average, they might be somewhat less happy (Bretz & Judge, 1994De Fruyt, 2002Verquer et al., 2003).

Admittedly, this whole line of argument is premised on the assumption that the wellbeing of individual STEM workers ought to be the deciding factor, and some might reject that assumption. Anyone who does, though, should, we think, be expected to make a strong argument for that position. Why should we put a statistical, collective goal – i.e. more equal sex ratios in STEM – above the happiness and autonomy of the flesh-and-blood individuals who constitute those collectives? Why should policy makers’ preference for gender parity take precedence over individual men and women’s preferences regarding their own careers and lives?15

Sex differences as a sign of social health

A recurring theme in discussions of occupational gender disparities is the often-unspoken assumption that sex differences are inherently problematic, or that they constitute direct evidence of sexism and the curbing of women’s opportunities. Some research, however, points to the opposite conclusion. A growing body of work suggests that, in nations with greater wealth and higher levels of gender equality, sex differences are often larger than they are in less wealthy, less equal nations. This is true for a wide range of variables, including aggression (Nivette et al., 2019), attachment styles (Schmitt, Alcalay, Allensworth, et al., 2003), the Big Five personality traits (Schmitt et al., 2008), crying (Van Hemert et al., 2011), depression (Hopcroft & McLaughlin, 2012), enjoyment of casual sex (Schmitt, 2015), interest in and enjoyment of science (Stoet & Geary, 2018), intimate partner violence (Schmitt, 2015), self-esteem (Zuckerman et al., 2016), spatial ability (Lippa et al., 2010), STEM graduation rates (Stoet & Geary, 2018), subjective wellbeing (Schmitt, 2015) and values (Falk & Hermle, 2018).16 Importantly, the pattern is also observed for objectively measurable traits such as height, BMI and blood pressure (Schmitt, 2015), which gives some reason to think that it is not simply a product of cross-cultural differences in the ways that people answer questionnaires or take tests.

What, then, is the cause of the pattern? One possibility is that when people grow up in an enriched and relatively unconstrained environment, nascent differences between individuals – and average differences between the sexes – have more opportunity to emerge and grow. In the case of psychological traits, the suggestion would be that men and women in wealthier, more developed nations have greater freedom to pursue what interests them and to nurture their own individuality. This freedom may, in turn, result in larger psychological sex differences (Schmitt et al., 2008; although see Fors Connolly et al., 2019Kaiser, 2019).

Regardless of the reason, though, if certain sex differences are larger in societies with better social indicators, then rather than being products of a sexist or oppressive society, these differences may be indicators of the opposite: a comparatively free and fair one. If so, this casts society’s efforts to minimize the sex differences in an entirely new light. Rather than furthering gender equality, such efforts may involve attacking a positive symptom of gender equality. By mistaking the fruits of our freedom for evidence of oppression, we may institute policies that, at best, burn up time and resources in a futile effort to cure a ‘disease’ that isn?t actually a disease, and at worst actively limit people’s freedom to pursue their own interests and ambitions on a fair and level playing field.

The sexist assumption underlying the demand for parity

Finally, the strong emphasis on increasing the numbers of women in male-dominated fields is arguably somewhat sexist. As Susan Pinker (2008) argues, it tacitly assumes that women do not know what they want, or that they want the wrong things and thus that wiser third-parties need to ‘fix’ their existing preferences. It also tacitly assumes that the areas where men dominate are superior. The psychologist Denise Cummins (2015) put the point well when she observed that, ‘The hidden assumption underlying the push to eliminate gender gaps in traditionally male-dominated fields is that such fields are intrinsically more important and more valuable to society than fields that traditionally attract more women.’ Given that traditionally female-dominated fields include education, healthcare and social work, this assumption is not only sexist; it is also clearly false. As Judith Kleinfeld observed:

We should not be sending [gifted] women the message that they are less worthy human beings, less valuable to our civilization, lazy or low in status, if they choose to be teachers rather than mathematicians, journalists rather than physicists, lawyers rather than engineers. (cited in Steven Pinker, 2002, p. 359)

Certainly, many female-dominated fields pay less, on average, than male-dominated STEM fields.17 There is a great deal of debate about the reasons for this, and the extent to which it is a product of sexism vs. factors such as market forces (e.g. the fact that many female-dominated fields have a greater supply of workers) and personal preferences (e.g. the fact that, on average, women view pay as a less important consideration in choosing a career than men, and view things such as job security and flexible work hours as more important; Funk & Parker, 2018Gino et al., 2015Lubinski et al., 2014Redmond & McGuinness, 2019). Such matters are beyond the scope of this article. We would point out, though, that even if current pay disparities were entirely due to sexism, the most appropriate solution would presumably be to strive for fair pay in female-dominated fields, rather than trying to get more women into fields that pay more but which, on average, they find less appealing. And to the extent that the explanation is that women place less weight on a high income in choosing a career, and more weight on other things, efforts to get women to prioritize income tacitly assume, once again, that women’s existing priorities are misguided, and that they ought to adopt more male-typical priorities instead.

To be clear, we completely agree that we should endeavour to root out sexism wherever it still lurks, and tear down any lingering barriers to the progress of women in STEM (as well as any barriers to the progress of men). These are eminently good goals. However, for the reasons discussed, striving for a 50:50 sex ratio – or indeed any pre-specified sex ratio – is not a good goal.

People regard a large number of friends as a signal of social capital that increases their interpersonal attractiveness, but they personally prefer to make friends with someone who has a relatively small number of friends

Si, K., Dai, X., & Wyer, R. S., Jr. (2021). The friend number paradox. Journal of Personality and Social Psychology, 120(1), 84–98, Jan 2021. https://doi.org/10.1037/pspi0000244

Abstract: We identify a friend number paradox, that is, a mismatch between people’s preferences for the friends they might acquire in social interactions and their predictions of others’ preferences. People predict that others are attracted to them if they have a relatively large number of friends. However, they personally prefer to make friends with someone who has a relatively small number of friends. People regard a large number of friends as a signal of social capital that increases their interpersonal attractiveness. However, it can actually be a signal of social liabilities that diminish their ability to reciprocate obligations to others. We conducted a series of studies, including 3 speed-friending studies in which participants either engaged or expected to engage in actual interactions for the purpose of initiating long-term friendships. These studies provide converging evidence of the hypothesized mismatch and our conceptualization of its determinants.


Universality of the Triangular Theory of Love: Adaptation and Psychometric Properties of the Triangular Love Scale in 25 Countries

Universality of the Triangular Theory of Love: Adaptation and Psychometric Properties of the Triangular Love Scale in 25 Countries. Piotr Sorokowski et al. The Journal of Sex Research, Volume 58, 2021 - Issue 1, Pages 106-115, Aug 12 2020. https://doi.org/10.1080/00224499.2020.1787318

The Triangular Theory of Love (measured with Sternberg’s Triangular Love Scale – STLS) is a prominent theoretical concept in empirical research on love. To expand the culturally homogeneous body of previous psychometric research regarding the STLS, we conducted a large-scale cross-cultural study with the use of this scale. In total, we examined more than 11,000 respondents, but as a result of applied exclusion criteria, the final analyses were based on a sample of 7332 participants from 25 countries (from all inhabited continents). We tested configural invariance, metric invariance, and scalar invariance, all of which confirmed the cultural universality of the theoretical construct of love analyzed in our study. We also observed that levels of love components differ depending on relationship duration, following the dynamics suggested in the Triangular Theory of Love. Supplementary files with all our data, including results on love intensity across different countries along with STLS versions adapted in a few dozen languages, will further enable more extensive research on the Triangular Theory of Love.

Wikipedia: Triangular theory of love - Wikipedia

Extramarital Sex among Chinese Men and Women: Among married adults aged 20–59, the occurrence rate of EMS nearly tripled over the period 2000–2015, going from 12.9% to 33.4% for men, & from 4.7% to 11.4% for women

Prevalence and Patterns of Extramarital Sex among Chinese Men and Women: 2000-2015. Yueyun Zhang, Xin Wang & Suiming Pan. The Journal of Sex Research , Volume 58, 2021 - Issue 1, Pages 41-50, Aug 12 2020. https://doi.org/10.1080/00224499.2020.1797617

Despite growing concern about the “sexual revolution” in China in the past decades, empirical evidence regarding the national trends in prevalence and patterns of extramarital sex (EMS) remains sparse. This study aimed to fill this gap, using data from a population-based, repeated cross-sectional survey administered at four time points during the period 2000–2015. EMS was assessed by asking whether a person in marriage had engaged in sexual activity with someone else during the relationship with his/her current partner. Our findings showed that among married adults aged 20–59, the occurrence rate of EMS nearly tripled over the period 2000–2015, increasing from 12.9% to 33.4% for men, and from 4.7% to 11.4% for women. Moreover, in the early years of this century, EMS was negatively associated with older age (50–59 years), lower educational level (elementary and below) and rural residence for men, and negatively associated with older age and positively associated with higher educational level (college and above) for women. All these differences, however, disappeared in more recent years. Overall, this study indicates a marked increase in EMS, a widening gender gap in EMS, and for each gender, a convergence of EMS across various sociodemographic groups.