Dissecting Discrimination

This Open-Access-book examines the phenomenon of discrimination using a descriptive approach. Discrimination is omnipresent, whether it is people who discriminate against other people or, more recently, also machines that discriminate against people. The first part of the analysis employs decision theory on discrimination, leading to two fundamental subtypes: taste-based discrimination and statistical discrimination. The second part links taste-based discrimination to social identity theory, demonstrates that not all taste-based discrimination is ultimately statistical discrimination, and reveals the evolutionary origins of our tastes. The third part surveys how people get their beliefs for statistical discrimination and thereby shows that they often deviate from Bayesianism: they have inherent prior beliefs and do not exclusively update their beliefs according to Bayes’ law. Additionally, the analysis of belief formation highlights the importance of the learning environment. The last part reassembles the previously dissected aspects of discrimination, presents a new descriptive model of discrimination, and lists five implications for a normative theory of discrimination

How Psychedelic-Assisted Treatment Works in the Bayesian Brain

Psychedelics are experiencing a renaissance in clinical research. In recent years, an increasing number of studies on psychedelic-assisted treatment have been conducted. So far, the results are promising, suggesting that this new (or rather, rediscovered) form of therapy has great potential. One particular reason for that appears to be the synergistic combination of the pharmacological and psychotherapeutic interventions in psychedelic-assisted treatment. But how exactly do these two interventions complement each other? This paper provides the first account of the interaction between pharmacological and psychological effects in psychedelic-assisted treatment. Building on the relaxed beliefs under psychedelics (REBUS) hypothesis of Carhart-Harris and Friston and the contextual model of Wampold, it argues that psychedelics amplify the common factors and thereby the remedial effects of psychotherapy. More precisely, psychedelics are assumed to attenuate the precision of high-level predictions, making them more revisable by bottom-up input. Psychotherapy constitutes an important source of such input. At best, it signalizes a safe and supportive environment (cf. setting) and induces remedial expectations (cf. set). During treatment, these signals should become incorporated when high-level predictions are revised: a process that is hypothesized to occur as a matter of course in psychotherapy but to get reinforced and accelerated under psychedelics. Ultimately, these revisions should lead to a relief of symptoms

The role of expectations in transformative experiences

According to L. A. Paul, the subjective value of an outcome is normally assessed by running a cognitive model of what it would be like if that outcome were to occur. However, cognitive models, along with the expectations in which they result, are unreliable for application to transformative experiences because we cannot know what it would be like for an outcome to occur if we have never experienced it before. This paper argues that despite their unreliability, expectations are still important in the case of chosen and unchosen transformative experiences because expectations about an outcome can systematically influence the very experience of that outcome. More precisely, empirical research shows that affective experiences tend to assimilate to affective expectations. In turn, more positive affective experiences lead, ceteris paribus, to higher subjective value. Therefore, rational agents confronting transformative outcomes should form or cultivate positive/optimistic affective expectations since, all else being equal, that maximizes subjective value

Probabilities of cooperative moves in all 67 symmetric ordinal two-player two-moves games

The symmetric 2x2 one-shot game is one of the simplest and most commonly used representations of strategic conflict. Among others, it includes the prisoner’s dilemma, the game of chicken, the volunteer’s dilemma, and the assurance game. All of these games share three characteristics: (1) both players have to make a single choice between two options; (2) they decide simultaneously; and (3) the payoff structure is symmetric. Typically, social scientists who examine (symmetric) 2x2 one-shot games either focus on one game or compare a small number of such games. There are comparatively few studies which analyzed (symmetric) 2x2 one-shot games in a more comprehensive manner. The goal of the present paper is to initiate research on the strategies people use to play any or all symmetric ordinal two-player two-moves games. We propose comparisons between eight different strategies. As will be shown, this analysis lays the groundwork for many possible follow-up projects

Stereotypes and self-fulfilling prophecies in the Bayesian brain

Stereotypes are often described as being generally inaccurate and irrational. However, for years, a minority of social psychologists has been proclaiming that stereotype accuracy is among the most robust findings in the field. This same minority also opposes the majority by questioning the power of self-fulfilling prophecies and thereby the construction of social reality. The present paper examines this long-standing debate from the perspective of predictive processing, an increasingly influential cognitive science theory. In this theory, stereotype accuracy and self-fulfilling prophecies are two sides of the same coin, namely prediction error minimisation, pointing to a new middle course between the two existing views. On the one hand, predictive processing indicates that depicting stereotypes as generally inaccurate runs counter to their actual purpose of making the social world predictable, which supports the minority view. On the other hand, predictive processing supposes that expectations, including stereotypes, permanently affect perception and behaviour and thereby co-construct social reality, which supports the majority view. Therefore, from a predictive processing perspective, stereotypes are largely rational and not per se inaccurate, and self-fulfilling prophecies are omnipresent and greatly affect social reality. This new middle course appears to fit the empirical data better than the two existing views

The Role of Certainty in a Two-Person Volunteer’s Dilemma

In the standard volunteer’s dilemma (VoD), a single prosocial act (i.e., volunteering) yields the optimal overall outcome. Whereas the volunteer’s outcome is certain, the defector’s outcome depends on what others do. This research addressed the confounding of prosocial responses with uncertainty avoidance in the standard VoD. In Experiment 1, participants (N = 102) considered 18 hypothetical one-shot two-person VoD scenarios with certain, risky, and uncertain outcomes when volunteering. In Experiment 2, participants (N = 496) considered three hypothetical one-shot two-person VoD scenarios; a certain VoD and two uncertain VoDs of which one had a lower expected collective outcome of volunteering than the certain VoD and the other a higher one. Results suggest that volunteering does not reflect a desire to avoid uncertainty but to maximize expected collective outcomes, reinforcing the assumption that the high volunteering rates we see in a standard VoD are due to social/moral preferences and social projection

High-resolution ultrasound confirms reduced synovial hyperplasia following rituximab treatment in rheumatoid arthritis

Objective. To assess the response of RA patients to rituximab (RTX) treatment using a sensitive imaging technique for synovitis. Methods. Twenty-three RA patients were treated with two 1000-mg infusions of the B-cell depleting antibody, RTX, in an observational protocol. Clinical response was assessed by the European League Against Rheumatism (EULAR) response criteria. High-resolution grey-scale and colour-coded power Doppler (PD) ultrasonography was performed at baseline and 6 months after RTX. The second to fifth MCP and PIP joints were bilaterally examined with joints in a neutral 0 position from a palmar view and scored from 0 to 3. Results. Median disease activity score (DAS28) improved from 5.03 to 3.56 (P = 0.001), which corresponded to a EULAR moderate response in 11 of 23 patients and a EULAR good response in another 6 patients. Improved control of disease activity by RTX was also indicated by tapering of median daily corticosteroid doses from 10 to 5 mg, without flare ups. Mean grey-scale scores correlated with the swollen joint count at baseline (r = 0.484, P = 0.022) and month 6 (r = 0.519, P = 0.011). Mean grey-scale scores improved upon RTX from a 0.90 median (range 0.13-1.87) to 0.75 (range 0.19-1.50, P = 0.023). Frequency of PD positive joints was low (6.1%) at baseline and did not significantly change following RTX treatment. Conclusions. High-resolution grey-scale ultrasonography (US) examination confirmed reduced synovial hyperplasia, but the applied PD method displayed no significant changes. Therefore, only grey-scale US is recommended in follow-up examinations after RTX treatmen

Patients with diffuse idiopathic skeletal hyperostosis do not have increased peripheral bone mineral density and geometry

Objectives. Recent studies have suggested that areal BMD (aBMD) measured by DXA is elevated in patients with DISH. We used peripheral QCT (pQCT) to assess volumetric BMD (vBMD) and bone geometry of the radius, tibia and the third metacarpal bone. Methods. Patients with established DISH and a control group of healthy individuals were recruited. pQCT measurements were performed at the distal epiphyses and mid-shafts of the radius, the tibia and the third metacarpal bone. At the epiphyses cross-sectional area (CSA), total BMD and trabecular BMD were measured. At the shafts, total bone CSA, cortical CSA, cortical wall thickness and cortical BMD were determined. In addition, muscle and fat CSA of the forearm and lower leg were assessed. Bone parameters were compared between the two groups using independent t-tests. Results. Thirty DISH patients and 30 controls comparable with regard to age and height were included in this study. None of the measured bone parameters differed between groups. Conclusions. In contrast to suggestions based on DXA, pQCT revealed that DISH patients do not have increased vBMD and bone geometry in the appendicular skeleton. Ossification at tendon or ligament insertion sites may lead to overestimation of aBMD if assessed by DX