Consistent individual differences in human social learning strategies

Social learning has allowed humans to build up extensive cultural repertoires, enabling them to adapt to a wide variety of environmental and social conditions. However, it is unclear which social learning strategies people use, especially in social contexts where their payoffs depend on the behaviour of others. Here we show experimentally that individuals differ in their social learning strategies and that they tend to employ the same learning strategy irrespective of the interaction context. Payoff-based learners focus on their peers’ success, while decision-based learners disregard payoffs and exclusively focus on their peers’ past behaviour. These individual differences may be of considerable importance for cultural evolution. By means of a simple model, we demonstrate that groups harbouring individuals with different learning strategies may be faster in adopting technological innovations and can be more efficient through successful role differentiation. Our study highlights the importance of individual variation for human interactions and sheds new light on the dynamics of cultural evolution

Foundations of cultural evolution:Introduction

'Cultural evolution' as a field applies the insight that cultural change may be like biological evolution. Concepts, methods and ideas from the well-established theory of biological evolution are applied to cultural processes, such as the spread and diversification of languages or technology. Some researchers even suggest that evolutionary theory may serve as a synthetic framework for unifying the humanities and the social sciences, just as biological evolution is viewed as a unifying principle underlying all life sciences. This theme issue examines the theoretical and methodological core of this rapidly expanding field. What premises form the foundation? What are the disparities? The issue unites perspectives and fosters dialogue between scholars across disciplines - breaking ground in the study of the dynamics and diversity of culture

Focus on the success of others leads to selfish behavior

It has often been argued that the spectacular cognitive capacities of humans are the result of selection for the ability to gather, process, and use information about other people. Recent studies show that humans strongly and consistently differ in what type of social information they are interested in. Although some individuals mainly attend to what the majority is doing (frequency-based learning), others focus on the success that their peers achieve with their behavior (success-based learning). Here, we show that such differences in social learning have important consequences for the outcome of social interactions. We report on a decision-making experiment in which individuals were first classified as frequency and success-based learners and subsequently grouped according to their learning strategy. When confronted with a social dilemma situation, groups of frequency-based learners cooperated considerably more than groups of success-based learners. A detailed analysis of the decision-making process reveals that these differences in cooperation are a direct result of the differences in information use. Our results show that individual differences in social learning strategies are crucial for understanding social behavior

High Protein Oral Nutritional Supplements Enable the Majority of Cancer Patients to Meet Protein Intake Recommendations during Systemic Anti-Cancer Treatment:A Randomised Controlled Parallel-Group Study

ESPEN guidelines recommend a minimum protein intake of 1.0 g/kg body weight (BW) per day to maintain or restore lean body mass in patients with cancer. During anti-cancer treatment, optimal protein intake is difficult to achieve. We investigated whether a high-protein, low-volume oral nutritional supplement (ONS) supports patients in meeting recommendations. A multi-centre, randomised, controlled, open-label, parallel-group study was carried out in nine hospitals (five countries) between January 2019 and July 2021 in colorectal and lung cancer patients undergoing first-line systemic treatment with chemo(radio-) or immunotherapy. Subjects were randomised (2:1) to receive Fortimel Compact Protein® or standard care. Protein intake was assessed with a 3-day food diary (primary outcome). BW was a secondary outcome. Due to challenges in recruitment, the study was terminated prematurely with 42 patients randomised (intervention group (IG) 28; control group (CG) 14). At T1 and T2, protein intake was statistically significantly higher in the IG compared to the CG (1.40 vs. 1.07 g/kg/day at T1, p = 0.008; 1.32 vs. 0.94 g/kg/day at T2, p = 0.002). At baseline, only 65% (IG) and 45% (CG) of patients met ESPEN minimum protein intake recommendations. However, at T1 and T2 in the IG, a higher proportion of patients met recommendations than in the CG (88% vs. 55% and 40%). No statistically significant difference between study groups was observed for BW. Mean compliance to the ONS was 73.4%. A high-protein, low-volume ONS consumed twice daily enables the majority of patients to reach minimal ESPEN protein recommendations.</p

High Protein Oral Nutritional Supplements Enable the Majority of Cancer Patients to Meet Protein Intake Recommendations during Systemic Anti-Cancer Treatment:A Randomised Controlled Parallel-Group Study

ESPEN guidelines recommend a minimum protein intake of 1.0 g/kg body weight (BW) per day to maintain or restore lean body mass in patients with cancer. During anti-cancer treatment, optimal protein intake is difficult to achieve. We investigated whether a high-protein, low-volume oral nutritional supplement (ONS) supports patients in meeting recommendations. A multi-centre, randomised, controlled, open-label, parallel-group study was carried out in nine hospitals (five countries) between January 2019 and July 2021 in colorectal and lung cancer patients undergoing first-line systemic treatment with chemo(radio-) or immunotherapy. Subjects were randomised (2:1) to receive Fortimel Compact Protein® or standard care. Protein intake was assessed with a 3-day food diary (primary outcome). BW was a secondary outcome. Due to challenges in recruitment, the study was terminated prematurely with 42 patients randomised (intervention group (IG) 28; control group (CG) 14). At T1 and T2, protein intake was statistically significantly higher in the IG compared to the CG (1.40 vs. 1.07 g/kg/day at T1, p = 0.008; 1.32 vs. 0.94 g/kg/day at T2, p = 0.002). At baseline, only 65% (IG) and 45% (CG) of patients met ESPEN minimum protein intake recommendations. However, at T1 and T2 in the IG, a higher proportion of patients met recommendations than in the CG (88% vs. 55% and 40%). No statistically significant difference between study groups was observed for BW. Mean compliance to the ONS was 73.4%. A high-protein, low-volume ONS consumed twice daily enables the majority of patients to reach minimal ESPEN protein recommendations.</p

Rigorous Inequalities between Length and Time Scales in Glassy Systems

Glassy systems are characterized by an extremely sluggish dynamics without any simple sign of long range order. It is a debated question whether a correct description of such phenomenon requires the emergence of a large correlation length. We prove rigorous bounds between length and time scales implying the growth of a properly defined length when the relaxation time increases. Our results are valid in a rather general setting, which covers finite-dimensional and mean field systems. As an illustration, we discuss the Glauber (heat bath) dynamics of p-spin glass models on random regular graphs. We present the first proof that a model of this type undergoes a purely dynamical phase transition not accompanied by any thermodynamic singularity.Comment: 24 pages, 3 figures; published versio

Mpox outbreak in the Netherlands, 2022: public health response, characteristics of the first 1,000 cases and protection of the first-generation smallpox vaccine

In early May 2022, a global outbreak of mpox started among persons without travel history to regions known to be enzootic for monkeypox virus (MPXV). On 8 August 2022, the Netherlands reported its 1,000th mpox case, representing a cumulative incidence of 55 per million population, one of the highest cumulative incidences worldwide. We describe characteristics of the first 1,000 mpox cases in the Netherlands, reported between 20 May and 8 August 2022, within the context of the public health response. These cases were pre-dominantly men who have sex with men aged 31-45 years. The vast majority of infections were acquired through sexual contact with casual partners in pri-vate or recreational settings including LGBTQIA+ ven-ues in the Netherlands. This indicates that, although some larger upsurges occurred from point-source and/or travel-related events, the outbreak was mainly characterised by sustained transmission within the Netherlands. In addition, we estimated the protective effect of first-generation smallpox vaccine against moderate/severe mpox and found a vaccine effective-ness of 58% (95% CI: 17-78%), suggesting moderate protection against moderate/severe mpox symptoms on top of any possible protection by this vaccine against MPXV infection and disease. Communication with and supporting the at-risk population in following mitigation measures remains essential.Immunogenetics and cellular immunology of bacterial infectious disease

Genome-wide analyses for personality traits identify six genomic loci and show correlations with psychiatric disorders

Personality is influenced by genetic and environmental factors1 and associated with mental health. However, the underlying genetic determinants are largely unknown. We identified six genetic loci, including five novel loci2,3, significantly associated with personality traits in a meta-analysis of genome-wide association studies (N = 123,132–260,861). Of these genomewide significant loci, extraversion was associated with variants in WSCD2 and near PCDH15, and neuroticism with variants on chromosome 8p23.1 and in L3MBTL2. We performed a principal component analysis to extract major dimensions underlying genetic variations among five personality traits and six psychiatric disorders (N = 5,422–18,759). The first genetic dimension separated personality traits and psychiatric disorders, except that neuroticism and openness to experience were clustered with the disorders. High genetic correlations were found between extraversion and attention-deficit– hyperactivity disorder (ADHD) and between openness and schizophrenia and bipolar disorder. The second genetic dimension was closely aligned with extraversion–introversion and grouped neuroticism with internalizing psychopathology (e.g., depression or anxiety)