Adult Learners in a Novel Environment Use Prestige-Biased Social Learning

Social learning (learning from others) is evolutionarily adaptive under a wide range of conditions and is a long-standing area of interest across the social and biological sciences. One social-learning mechanism derived from cultural evolutionary theory is prestige bias, which allows a learner in a novel environment to quickly and inexpensively gather information as to the potentially best teachers, thus maximizing his or her chances of acquiring adaptive behavior. Learners provide deference to high-status individuals in order to ingratiate themselves with, and gain extended exposure to, that individual. We examined prestige-biased social transmission in a laboratory experiment in which participants designed arrowheads and attempted to maximize hunting success, measured in caloric return. Our main findings are that (1) participants preferentially learned from prestigious models (defined as those models at whom others spent longer times looking), and (2) prestige information and success-related information were used to the same degree, even though the former was less useful in this experiment than the latter. We also found that (3) participants were most likely to use social learning over individual (asocial) learning when they were performing poorly, in line with previous experiments, and (4) prestige information was not used more often following environmental shifts, contrary to predictions. These results support previous discussions of the key role that prestige-biased transmission plays in social learning

The Cultural Transmission of Prestige and Dominance Social Rank Cues: an Experimental Simulation

This is the final version. Available from Springer via the DOI in this record.Below is the link to the dataset and preview of the experiment, and Dataset (CSV, 133KB) - process_raw_data_included.csv can be found in the Electronic Supplementary Material section Preview of the experiment: https://exetercles.eu.qualtrics.com/jfe/form/SV_071cfHiCY9qBEkB.Informal social hierarchies within small human groups are argued to be based on prestige, dominance, or a combination of the two (Henrich & Gil-White, 2001). Prestige-based hierarchies entail the ordering of individuals by the admiration and respect they receive from others due to their competence within valued domains. This type of hierarchy provides benefits for subordinates such as social learning opportunities and both private and public goods. In contrast, dominance-based hierarchies entail the ordering of individuals by their capacity to win fights, and coerce or intimidate others. This type of hierarchy produces costs in subordinates due to its aggressive and intimidating nature. Given the benefits and costs associated with these types of social hierarchies for subordinates, we hypothesised that prestige and dominance cues are better recalled and transmitted than social rank cues that do not elicit high prestige or dominance associations (i.e. medium social rank cues). Assuming that for the majority of the population who are not already at the top of the social hierarchy it is more important to avoid the costs of dominance-based hierarchies than to obtain the benefits of prestige-based hierarchies, we further hypothesised that dominance cues are better transmitted than prestige cues. We conducted a recall-based transmission chain experiment with 30 chains of four generations each (N = 120). Participants read and recalled descriptions of prestigious, dominant, and medium social rank footballers, and their recall was passed to the next participant within their chain. As predicted, we found that both prestige cues and dominance cues were better transmitted than medium social rank cues. However, we did not find support for our prediction of the better transmission of dominance cues than prestige cues. We discuss whether the results might be explained by a specific social-rank content transmission bias or by a more general emotional content transmission bias.University of Exete

Cultural Phylogenetics of the Tupi Language Family in Lowland South America

Background: Recent advances in automated assessment of basic vocabulary lists allow the construction of linguistic phylogenies useful for tracing dynamics of human population expansions, reconstructing ancestral cultures, and modeling transition rates of cultural traits over time. Methods: Here we investigate the Tupi expansion, a widely-dispersed language family in lowland South America, with a distance-based phylogeny based on 40-word vocabulary lists from 48 languages. We coded 11 cultural traits across the diverse Tupi family including traditional warfare patterns, post-marital residence, corporate structure, community size, paternity beliefs, sibling terminology, presence of canoes, tattooing, shamanism, men’s houses, and lip plugs. Results/Discussion: The linguistic phylogeny supports a Tupi homeland in west-central Brazil with subsequent major expansions across much of lowland South America. Consistently, ancestral reconstructions of cultural traits over the linguistic phylogeny suggest that social complexity has tended to decline through time, most notably in the independent emergence of several nomadic hunter-gatherer societies. Estimated rates of cultural change across the Tupi expansion are on the order of only a few changes per 10,000 years, in accord with previous cultural phylogenetic results in other languag

Importance of a lipopolysaccharide-containing extracellular toxic complex in infections produced by Klebsiella pneumoniae

A Klebsiella pneumoniae serotype 2 strain was examined for its ability to produce extracellular toxic material. The organism was grown to the stationary phase in a defined medium, and the toxic material was isolated by ultrafiltration-ion-exchange chromatography on DEAE-Sephacel and gel filtration chromatography on Sepharose 4B or 2B. It was found to be comprised of 63% capsular polysaccharide, 30% lipopolysaccharide, and 7% protein and possessed a 50% lethal dose (when injected intraperitoneally into mice) of 393 +/- 45 micrograms. The toxicity appeared to be associated with the endotoxin portion of the compound, because boiling for 15 min and exposure to proteolytic enzymes had no effect on the toxicity. However, saponification destroyed the toxicity of the compound. Studies employing radial immunodiffusion examining the sera of mice infected with this organism demonstrated in vivo production of the complex at levels sufficiently high to produce death. When sublethal amounts of this complex were placed in the lungs of specific-pathogen-free mice, the lung pathology observed after 24, 48, and 72 h was similar to the damage caused by an active K. pneumoniae lobar pneumonia. These data indicate that this extracellular toxic compound produced by K. pneumoniae may be responsible for the lethality and lung tissue destruction normally associated with an active lobar pneumonia caused by this organism.</jats:p

Incidence reduction of sexually transmitted hpv

"Through a literature review, the objective formed was to identify the optimum technique to reduce the incidence of sexually contracted HPV."--Objective

Where\u27s Dad? The Importance of Integrating Fatherhood and Parenting Programming into Substance Use Treatment for Men

Large numbers of men enter substance use disorder treatment each year, yet very little attention is paid to the fatherhood and parenting status of these men. Substance use treatment programmes for men rarely incorporate a parenting component into their treatment planning, despite the increased success of women\u27s treatment programmes that focus on gender and motherhood. This paper provides: (1) a review of the literature on the fathering of substance‐using men, what has been learned from substance use disorder treatment for mothers, and the implications for children and families; (2) pilot quantitative and qualitative outcomes resulting from the implementation of a fatherhood‐focused intervention for men in a residential substance use treatment programme; and (3) recommendations for the application of these findings for fathers in substance use disorder treatment, and considers the implications of programme modifications and increased focus on fathers for child welfare