Thursday, February 3, 2022

In Sweden, men with limited resources are considered less attractive; male financial resources are not seen as a bonus, but rather a prerequisite; sexual exchange theory is then a useful theory

Ngaosuvan, Leonard and Holmberg, Linus Carl and Saleh Al-Basri, Naila and Elshani, Rebecca, Sexual Economics in Swedish Dating: Pity Poor Men. SSRN, Jan 29 2022:

Abstract: Sexual exchange theory (SET) is a controversial theory describing heterosexual partner selection in terms of economic market factors. This paper explores SET empirically in Sweden, one of the most financially equal nations in the world. Experiment 1, a vignette study with four dating profiles, tested whether access to resources increases male attractiveness. Experiment 2, a vignette study measured how justifiable men’s disappointment was, depending on financial courtship investments in a failed courtship attempt. The results of Experiment 1 indicated that, even in Sweden, men with limited resources are considered less attractive. Male financial resources are not seen as a bonus, but rather a prerequisite. In Experiment 2, participants felt that it was not justifiable to be disappointed for men who were ‘cheap’ in courtship. These results indicate that SET is a useful theory, even in a relatively gender-equal society.

Keywords: Sexual Economics, Gender equality, Partner Selection, Attraction, Courtship, Sexual Exchange Theory.

Psychedelics: Medical risks are often minimal, and that many – albeit not all – of the persistent negative perceptions of psychological risks are unsupported by the currently available scientific evidence

Adverse effects of psychedelics: From anecdotes and misinformation to systematic science. Anne K Schlag et al. Journal of Psychopharmacology, February 2, 2022.


Background: Despite an increasing body of research highlighting their efficacy to treat a broad range of medical conditions, psychedelic drugs remain a controversial issue among the public and politicians, tainted by previous stigmatisation and perceptions of risk and danger.

Objective: This narrative review examines the evidence for potential harms of the classic psychedelics by separating anecdotes and misinformation from systematic research.

Methods: Taking a high-level perspective, we address both psychological and psychiatric risks, such as abuse liability and potential for dependence, as well as medical harms, including toxicity and overdose. We explore the evidence base for these adverse effects to elucidate which of these harms are based largely on anecdotes versus those that stand up to current scientific scrutiny.

Results: Our review shows that medical risks are often minimal, and that many – albeit not all – of the persistent negative perceptions of psychological risks are unsupported by the currently available scientific evidence, with the majority of reported adverse effects not being observed in a regulated and/or medical context.

Conclusions: This highlights the importance for clinicians and therapists to keep to the highest safety and ethical standards. It is imperative not to be overzealous and to ensure balanced media reporting to avoid future controversies, so that much needed research can continue.

Keywords: Psilocybin, dimethyltryptamine, ayahuasca, mescaline, d-lysergic acid diethylamide, abuse liability/dependence, hallucinogen persistent perception disorder, toxicity, hypertension

Some of the perceived harms of psychedelics – for example, that they lead to addiction and are neurotoxic – are largely refuted by research of the past decades. Other risks, such as the risks of psychotic episodes or overdose, are rare and only reported in individual cases, but these risks still need to be minimised by careful patient selection and preparation. The past decade of research and clinical experience has increasingly demonstrated how psychedelics can be used safely under medical supervision, and safe use guidelines are progressively well defined (e.g. Griffiths et al., 2006).

Regulatory and legal hurdles of getting psychedelic medicines proven as mainstream medicines are still substantial, so overcoming historic misperceptions is vital. The past decade has seen an increasing focus on research on the therapeutic applications of psychedelics – a direct benefit for the public, which is positively represented in current media (Aday et al., 2019). A recent YouGov study (2017) indicates that public perceptions in the United States becoming more positive, with the majority (63%) being open to medical treatment with psychedelics if faced with a pertinent medical condition, and a UK YouGov survey (2021) corroborates these results.

These changes in public interest are in line with the recent regulatory changes in the United States and Canada. Collectively, these changes in public perception and regulation suggest that the stigma surrounding psychedelics may be beginning to dissipate, and that society is moving away from previous negative narratives to a more scientific, evidence-based approach to risks and benefits of psychedelics as medicine.

Political Resources and Online Political Hostility: How and Why Hostility Is More Prevalent Among the Resourceful

Rasmussen, Stig H. R., Mathias Osmundsen, and Michael Bang Petersen. 2022. “Political Resources and Online Political Hostility: How and Why Hostility Is More Prevalent Among the Resourceful.” PsyArXiv. February 2.

Abstract: Toxicity and hostility permeate political debates on social media, but who is responsible? Canonical theories of political engagement equate political resources with being a “model democratic citizen.” In contrast, we develop the theoretical argument that in the current polarized political climate, those same resources come to motivate hostile engagement. Combining two years of survey and behavioral Twitter data, we provide empirical support for a link between political resources and online political hostility. This link is especially pronounced among citizens high in affective polarization -- a trait held by many resourceful citizens in current US society. Concerningly, resourceful but hateful social media users do not simply cater to fringe audiences. Rather, they dominate online debates by tweeting more frequently, having more friends and followers, and by occupying powerful positions in their online networks. The present findings thus shed important light on the causes and consequences of online political hostility.

Human adult neurogenesis seems unlikely: Found signatures of adult neurogenesis in mouse, pig, and macaque dentate gyrus, but not in humans, adding to a growing body of evidence that this process is likely lost in humans

Transcriptomic taxonomy and neurogenic trajectories of adult human, macaque, and pig hippocampal and entorhinal cell. Daniel Franjic et al. Neuron, Volume 110, Issue 3, February 2 2022, Pages 452-469.e14.


• Single-nucleus RNA-seq of adult hippocampal-entorhinal cells in human, monkey, and pig

• Transcriptomic signatures of adult neurogenesis in mouse, pig, and monkey but not human

• Excitatory neuron diversification delineates transitions from 3- to 6-layered cortex

• METTL7B defines subregion-specific excitatory neurons and astrocytes in primates

Summary: The hippocampal-entorhinal system supports cognitive functions, has lifelong neurogenic capabilities in many species, and is selectively vulnerable to Alzheimer’s disease. To investigate neurogenic potential and cellular diversity, we profiled single-nucleus transcriptomes in five hippocampal-entorhinal subregions in humans, macaques, and pigs. Integrated cross-species analysis revealed robust transcriptomic and histologic signatures of neurogenesis in the adult mouse, pig, and macaque but not humans. Doublecortin (DCX), a widely accepted marker of newly generated granule cells, was detected in diverse human neurons, but it did not define immature neuron populations. To explore species differences in cellular diversity and implications for disease, we characterized subregion-specific, transcriptomically defined cell types and transitional changes from the three-layered archicortex to the six-layered neocortex. Notably, METTL7B defined subregion-specific excitatory neurons and astrocytes in primates, associated with endoplasmic reticulum and lipid droplet proteins, including Alzheimer’s disease-related proteins. This resource reveals cell-type- and species-specific properties shaping hippocampal-entorhinal neurogenesis and function.


We report an extensive single-cell transcriptomics analysis of several anatomically defined cell populations in the adult human, macaque, and pig hippocampal-entorhinal system. Our findings reveal fundamental species differences in adult hippocampal neurogenesis and delineate the molecular diversity of the cytoarchitectural transition from the allo- to the neocortex. These results also outline genes that are selectively enriched in certain species and cell types that may have a role in the specific biology and/or pathology of the hippocampal-entorhinal system

Unlike recent studies that mostly rely on one or two key markers (e.g., progenitors [nestin]; neuroblasts and immature granule cells [DCX]) (Boldrini et al., 2018Moreno-Jiménez et al., 2019Tobin et al., 2019), single-cell RNA-seq studies are more comprehensive because they leverage combinatorial gene expression profiles to identify cell populations more robustly (Hochgerner et al., 2018). This approach also allows cross-species analysis, amplifying rare signals within a single species that may be masked when analyzed separately. Our cross-species analysis allowed identification of the neurogenic lineage in the mouse, pig, and macaque, which was virtually absent in the human. We only detected one cell with the transcriptomics profile characteristic of nIPCs and one with putative neuroblast profile among 32,067 granule cells (0.003%) in our adult human DG samples, a proportion considerably lower than the expected 0.09%–3.8% neuroblasts according to previous DCX immunostaining or 14C incorporation studies of the adult human HIP (see Table S2 for data and relevant studies).

The same analytic strategy detected much higher proportions of neuroblasts in the other analyzed species (mouse, 6.6%; pig, 55.6%; macaque, 2.0%; Figure 2B; Table S3). These proportions were higher than those estimated previously based on progenitor proliferation and identification of neuroblasts markers such as DCX (Table S2), suggesting that more studies are needed to fine-tune detection of these neurogenic populations. However, this apparently lax detection protocol confirms that our parameters are unlikely to have missed any appreciable neuroblast populations among the large pool of surveyed human DG granule cells, even if they might exhibit an ambiguous profile.

Alternative confounding of our cross-species integrative analysis from possible human-specific transcriptomics changes was ruled out when human UMAP layouts did not include any clustering of neurogenic cells adjacent to the mature granule cell cluster. Likewise, the possibility that human neuroblasts exist in our samples but that their transcriptomics profile differs from other species and blends with related cell populations is lessened by findings that all neurogenic lineages preceding mature granule cells were absent in human DG samples (Tables S2 and S3).

We also extended our findings to existing snRNA-seq data of the adult human HIP. We reappraised the identity of a recently reported neural progenitor cluster (Ayhan et al., 2021) marked by LPAR1, a gene reported to mark mouse DG neural progenitors (Walker et al., 2016Hochgerner et al., 2018). Our analyses indicated that this cluster actually represented doublets formed by oligodendrocytes and granule cells (Figure S3S). In addition, reanalysis of the pioneer HIP data (Habib et al., 2017) by Sorrells et al. (2021) showed that the cell cluster labeled as neural stem cells was actually characteristic of ependymal cells.

Analysis of DCX transcripts in all the analyzed species showed expression in mature neurons, mostly InNs, and in glial cells, indicating that DCX expression is not exclusive to DG neuroblasts (Figures 3A and 3B). This pattern is in agreement with the reanalysis of the data from Habib et al. (2017) (Sorrells et al., 2021). All transcriptomics analyses performed so far suggest a lack of neurogenic cell populations in the adult human DG.

At the protein level, DCX was, with a few exceptions (Figure S3L), present exclusively in DG cells resembling neuroblasts and immature granule cells in all analyzed non-human species. Also, cells with immature morphology could be detected in other areas, such as the EC of the macaque or the pyriform cortex of the mouse, as described previously (Gómez-Climent et al., 2008Zhang et al., 2009). In humans, there is intense controversy regarding DCX immunostaining in the human DG, with some reports showing negative results (Dennis et al., 2016Cipriani et al., 2018Sorrells et al., 20182021) and others describing DCX-IL cells (Knoth et al., 2010Epp et al., 2013Boldrini et al., 2018Le Maître et al., 2018Moreno-Jiménez et al., 20192021Tobin et al., 2019). We detected clear DCX-IL cells in the amygdala and occasionally in the EC, but we could not find DCX-IL cells resembling neuroblasts in the DG in the same tissue sections. These inconsistencies in detecting DCX-IL cells in the adult human DG cannot be fully attributed to postmortem denaturation and degradation of DCX protein because DCX-IL cells were clearly detected in samples with prolonged PMIs (Figures S3D, S3E, and S3I–S3L). Moreno-Jiménez et al. (2019) reported an intensive protocol for antigen retrieval as a necessary step to label DCX cells in the human DG. However, they reported no positive cells in the EC, a relatively common finding in our study (Figure S3D) and another (Sorrells et al., 2021) using conventional antigen retrieval. Because our analysis did not reveal neuroblasts at the RNA or protein level (using diverse antigen retrieval methods), the question remains what those previously reported cells could be. Apart from underappreciated non-specific and off-target effects (Sorrells et al., 2021), those studies could label mature granule cells and InNs that might contain low levels of DCX protein that was detected specially after multi-step antigen retrieval. In support of this hypothesis is the fact that the faintly immunolabeled cells we detected mostly in the vicinity of the granule cell layer, exhibited the morphology of mature InNs, and some co-labeled with antibodies against GAD1, a marker of InNs (Figures 3E and S3M–S3Q). This faint staining is far from the strong staining and well-defined morphology of somata and dendrites revealed in the EC and in the amygdala (Figures S3D and S3E) and is similar to the light DCX immunostaining reported previously (Seki et al., 2019). Thus, our conclusion is that DCX protein might be expressed at very low levels in InNs or in some mature granule cells that can be lightly immunolabeled under normal antigen retrieval but can show more intense and widespread staining under more elaborate tissue treatment and stringent conditions of antigen retrieval. In fact, Figure 2I from Moreno-Jiménez et al. (2019) shows that around 75% of DCX-IL cells were colocalized with NeuN (RBFOX3, 75%), a marker of mature granule cells, and 91% of DCX-IL cells were also positive for Prospero homeobox1 (PROX1), a transcription factor expressed by granule cells that is also expressed by InNs generated in the caudal ganglionic eminence (Ma et al., 2013Laclef and Métin, 2018), supporting the possibility that most DCX-IL cells might actually be mature granule cells or InNs.

Regarding RNA analysis, although the PMI for humans was longer than for other analyzed species, human brains were kept at 4°C for most of the PMI period, whereas the pigs used as controls for PMI were kept at room temperature. This warm PMI will likely exacerbate the postmortem effects, but those conditions were not an obstacle to detect the neurogenic pathway in this species. It could be argued that the neurogenic pathway in the human DG is not detected because our snRNA-seq strategy might preferentially exclude neurogenic cells in humans. However, it seems extremely unlikely that it will affect all cell types in the neurogenic lineage, from progenitors to neuroblasts, and only in human. Overall, the most parsimonious interpretation of the combined results from our RNA transcript analysis and the DCX protein study is that, contrary to the other analyzed mammals, ongoing baseline neurogenesis does not occur or is extremely rare in the adult human DG.

Similar species-related and cell-specific transcriptomics profiling that characterizes neurogenic potential also outlines the transition from allocortical to neocortical domains in the hippocampal-entorhinal system and shows that ExNs are the main drivers of the differences between subfields (Figure 4), which evidences a richer complement of ExNs than traditional descriptions based on cytoarchitecture. Our analysis provides a primer to further study these populations and characterize the possible implications for hippocampal-entorhinal physiology. These data refine our understanding of the evolution of the allo-, meso-, and neocortex. The transcriptomics signatures we developed strongly suggest homology between the mammalian allocortex and specifically deep layers of the EC and neocortex.

Among the genes contributing to the layer transition, we identified METTL7B to be important in hippocampus physiology and function. We found that METTL7B, equipped with methyltransferase activity, interacts with important AD-related proteins (e.g., APP, LRP1, RTN3, and RTN4). Importantly, our results suggest that these functional interactions in a subset of ExNs and astrocytes seem to be phylogenetically specific to Old World monkeys and apes (parvorder Catarrhini), species that show more marked signs of pathology related to aging, such as AD, than other species (Perez et al., 2013Finch and Austad, 2015Edler et al., 2017Paspalas et al., 2018). Overall, our analyses provide multiple vignettes of how this resource can be used to identify cell types and genes that might be functionally relevant for the biology of the hippocampus, allowing inter-species comparisons.

Nudges: Our megastudy with 689,693 Walmart pharmacy customers demonstrates that text-based reminders can encourage pharmacy vaccination

A 680,000-person megastudy of nudges to encourage vaccination in pharmacies. Katherine L. Milkman et al. Proceedings of the National Academy of Sciences, February 8, 2022 119 (6) e2115126119;

Significance: Encouraging vaccination is a pressing policy problem. Our megastudy with 689,693 Walmart pharmacy customers demonstrates that text-based reminders can encourage pharmacy vaccination and establishes what kinds of messages work best. We tested 22 different text reminders using a variety of different behavioral science principles to nudge flu vaccination. Reminder texts increased vaccination rates by an average of 2.0 percentage points (6.8%) over a business-as-usual control condition. The most-effective messages reminded patients that a flu shot was waiting for them and delivered reminders on multiple days. The top-performing intervention included two texts 3 d apart and stated that a vaccine was “waiting for you.” Forecasters failed to anticipate that this would be the best-performing treatment, underscoring the value of testing.

Abstract: Encouraging vaccination is a pressing policy problem. To assess whether text-based reminders can encourage pharmacy vaccination and what kinds of messages work best, we conducted a megastudy. We randomly assigned 689,693 Walmart pharmacy patients to receive one of 22 different text reminders using a variety of different behavioral science principles to nudge flu vaccination or to a business-as-usual control condition that received no messages. We found that the reminder texts that we tested increased pharmacy vaccination rates by an average of 2.0 percentage points, or 6.8%, over a 3-mo follow-up period. The most-effective messages reminded patients that a flu shot was waiting for them and delivered reminders on multiple days. The top-performing intervention included two texts delivered 3 d apart and communicated to patients that a vaccine was “waiting for you.” Neither experts nor lay people anticipated that this would be the best-performing treatment, underscoring the value of simultaneously testing many different nudges in a highly powered megastudy.

Keywords: vaccinationCOVID-19nudgeinfluenzafield experiment


The results of this megastudy suggest that pharmacies can increase flu vaccination rates by sending behaviorally informed, text-based reminders to their patients. Further, although all interventions tested increased vaccination rates, there was significant variability in their effectiveness. Attribute analyses suggest that the most-impactful interventions employed messages sent on multiple days and conveyed that a flu vaccine was already waiting for the patient. These insights from our megastudy of flu vaccinations can potentially inform efforts by pharmacies and hopefully also providers and governments around the world in the ongoing campaign to encourage full vaccination against COVID-19.

The first- and second-best-performing messages in our megastudy repeatedly reminded patients to get a vaccine and stated that a flu shot was “waiting for you.”§ This aligns with prior research suggesting multiple reminders can help encourage healthy decisions (13). In terms of message content, communicating that a vaccine is “waiting for you” may increase the perceived value of vaccines, in accord with research on the endowment effect showing that we value things more if we feel they already belong to us (33). Further, because defaults convey implicit recommendations, this message may imply that the pharmacy is recommending vaccination (34)—otherwise, why would they have allocated a dose to you? Relatedly, this phrasing implies that the patient already agrees that getting the vaccine is desirable. Finally, saying a vaccine is “waiting for you” may suggest that getting a vaccine will be fast and easy.

Remarkably, the three top-performing text messages in a different megastudy, which included different intervention messages encouraging patients to get vaccines at an upcoming doctor’s visit, similarly conveyed to patients that a vaccine was “reserved for you.” (8) The Walmart megastudy tested a wide range of different messaging tactics designed by different researchers to explore largely different hypotheses such that the two megastudies had very limited overlap in their content. Further, our outcome variable here was electing to get a vaccine in a Walmart pharmacy, whereas the prior megastudy examined whether patients accepted a proffered vaccine in a doctor’s office. Despite differences in the messenger (pharmacy versus primary care provider), the outcome (seeking a vaccine at a pharmacy versus passively accepting one in a doctor’s office), and the messages actually tested, and despite analyzing our data without incorporating any priors, the results of the two megastudies converged, painting a consistent picture of what works. Together, this evidence suggests that sending reminder messages conveying that vaccines are “reserved” or “waiting” for patients is an especially effective communications strategy in the two most-common vaccination settings in the United States (16). While more research is needed to establish boundary conditions, it is notable that a follow-up study that built on the findings from these two megastudies and adapted the best-performing treatment to nudge COVID-19 vaccinations in the winter of 2021 found convergent results (9).

The scientists who designed interventions in our megastudy were not able to accurately forecast the average or relative performance of text message interventions designed to boost vaccinations. In contrast, lay survey respondents made fairly accurate predictions of both. This contradicts past research showing that experts are generally better at predicting the effectiveness of behavioral interventions than nonexperts (35). One possible explanation is that direct involvement in the design of interventions led to bias. Another possibility is that nonexperts are generally more-accurate relative forecasters in this particular field setting. Regardless, the inability of either scientists or laypeople to anticipate the top-performing intervention underscores the value of empirical testing when seeking the best policy.

The strengths of this megastudy include its massive, national sample, statistical power, an objective measure of vaccination obtained longitudinally over a 3-mo follow-up period, and simultaneous comparison of many different interventions. Several important weaknesses are also worth noting. First, we were only able to measure the impact of our interventions on vaccinations received at Walmart pharmacies. We cannot assess whether interventions increased vaccinations in other locations or, in fact, crowded out vaccinations in other settings. Past research found no meaningful evidence of crowd-in or crowd-out from reminder messages nudging vaccine adoption (4), but we cannot rule out either possibility. Another limitation is that the population studied only included patients who had received an influenza vaccine at a Walmart pharmacy in the prior flu season and agreed to receive SMS communications from Walmart pharmacy. Even so, our key findings are consistent with a different megastudy nudging vaccination at doctors’ visits (8), in which results were not moderated by prior vaccination status. It would be ideal to replicate and extend this megastudy with patients who have no prior history of vaccination. Relatedly, while we did not observe meaningful heterogeneity in treatment effects by available demographics, future research exploring heterogeneous treatment effects with a richer set of individual difference variables would be valuable.