Learning From Mistakes: Decision-making Biases Within the Primate Lineage

Humans and animals alike make thousands of decisions each day, and good decision-making is crucial to survive and thrive in a competitive world. Much research has focused on how to make ‘rational’ decisions based on stable and absolute preferences. In reality, however, human and animal decisions are extremely context dependent. We show and act on relative rather than absolute preferences (e.g., relative to irrelevant options, previous choices, or what others receive), and these tendencies can lead to consistently ‘irrational’ behavior. Studying the flaws in our cognitive system can help us learn how it works. This dissertation explored the extent to which we share several such decision-making biases with other primates. In a series of manual and computerized tasks, capuchin monkeys’ and rhesus macaques’ choices shifted in response to theoretically irrelevant factors like the presence of unattainable options, inferior options, or social partners; how much work they had previously invested; and how frequently different stimuli were encountered. These findings suggest that evolutionary ancient mechanisms can underlie similar biases in humans, highlighting the need to evaluate the potential function of decision-making strategies in a species’ physical and social environment. However, seemingly minor aspects of the experimental paradigms, like monkeys’ baseline preferences or whether information about the reward contingencies was signaled, affected the magnitude of these biases. Such methodological details may contribute to mixed evidence for decision-making biases in animals and need to be assessed systematically for comparative research to make valid inferences. In doing so, studying whether species other than humans make similar mistakes allows us to better understand the underlying cognitive mechanisms and the evolutionary forces that shape them

Rational Fools: (Ir)rational Choices of Humans, Rhesus Macaques, and Capuchin Monkeys in Dynamic Stochastic Environments

Human and animal decision-making is known to violate rational expectations in a variety of contexts. Statistical structures of real-world environments may account for such seemingly irrational behavior. In a computerized experiment, 16 capuchins, 7 rhesus monkeys, and 30 humans chose between up to three options of different value. The options disappeared and became available again with different probabilities. Subjects overwhelmingly chose transitively (A\u3eB, B\u3eC, and A\u3eC) in the control condition, where doing so maximized overall gain. However, most subjects also adhered to transitivity in the test condition, where it was suboptimal but led to negligible losses compared to the optimal strategy. Only a few of the capuchins were able to maximize long-term gain by violating transitivity. Adhering to rational choice principles may facilitate the formation of near-optimal decision rules when short- and long-term goals align. Such cognitive shortcuts may have evolved to preserve mental resources

Die Rolle von Emotionen beim Teamlernen - Affektive und kognitive Komponenten in der Teamarbeit von interdisziplinären Arbeitsteams an beruflichen Schulen

Arbeitsteams werden in Organisationen eingesetzt, um komplexe und wissensintensive Arbeitsaufgaben für Organisationen zu erfüllen. Wenn Arbeitsteams ihre Aufgaben erfüllen, findet das Lernen als Nebenprodukt in der Teamarbeit statt, indem die Teammitglieder miteinander interagieren. Die Teamarbeit von Arbeitsteams kann gefördert werden, indem die Teammitglieder unterstützt werden Teamlernaktivitäten auszuführen. Auf diese Weise können die Teammitglieder durch ihre eigenen Emotionen, aber auch durch emotionale Reaktionen anderer Teammitglieder beeinflusst werden. Daher ist es notwendig, die Rolle von Emotionen beim Teamlernen während der Teamarbeit zu untersuchen. In der bisherigen Forschung zu Teamlernen wurde vernachlässigt, Emotionen als Teamlernbedingungen zu berücksichtigen. Diese Forschungslücke wird in der vorliegenden Dissertation durch die Kombination von bisher zwei getrennten Forschungstraditionen, nämlich Teamlernen und Emotionen, geschlossen. Das Verständnis für kognitive und affektive Komponenten in der Teamarbeit wird erweitert, indem ein vertiefender Einblick in die Rolle von Emotionen beim Teamlernen während der Teamarbeit am Arbeitsplatz geben wird. Um dieses Ziel zu erreichen, wird die folgende Forschungsfrage beantwortet: Welche Rolle spielen Emotionen beim Teamlernen in der Teamarbeit am Arbeitsplatz? Die Forschungsfrage wird auf der Grundlage der Ergebnisse von drei empirischen Studien, welche unterschiedliche Teilziele verfolgten, beantwortet. Zudem wurden in dem Design der empirischen Studien zwei Kriterien berücksichtigt: Zum einen galt es unterschiedliche Forschungsmethoden zu verwenden und zum anderen verschiedene Systemebenen zu berücksichtigen. Das Teilziel der ersten Vorstudie war, zwei Kategoriensysteme zu entwickeln, um Teamlernaktivitäten und emotionale Reaktionen während der Teamarbeit anhand von qualitativen Forschungsmethoden zu untersuchen (individuelle Ebene). Die Entwickelten Kategoriensysteme wurden in der Hauptstudie verwendet. Die Daten wurden mit Hilfe von Beobachtungen von selbstorganisierten Teambesprechungen von Studierendenteams gesammelt (N=5, n=11). Das Teilziel der zweiten Vorstudie war, die Auswahl von Arbeitsteams für eine vertiefende Beobachtungsstudie der Hauptstudie zu identifizieren. Um dieses zu erreichen, war es notwendig, Unterschiede in den Teamlernaktivitäten und in den erlebten Emotionen von interdisziplinären Arbeitsteams (N=117, n=604) zu untersuchen (Teamebene). Das Teilziel der Hauptstudie war, Teamlernaktivitäten und Emotionen sowie ihre Verbindung über die Zeit zu untersuchen (Individuelle und Teamebene). Diese Studie bestand aus zwei Teil-Längsschnittstudien, einer Fragebogenerhebung (Teil I; N=67, n=278) und einer vertiefenden Beobachtungsstudie (Teil II; N=6, n=41). Die Ergebnisse der drei empirischen Studien sowie die Diskussion dieser mündeten in insgesamt fünf Schlussfolgerungen, anhand welcher die Forschungsfrage dieser Dissertation beantwortet wurde. Insbesondere werden die drei Schlussfolgerungen (3-5), welche aus den Ergebnissen der Hauptstudie abgeleitet wurden, im Folgenden genannt. (3) Wenn Teammitglieder positive emotionale Reaktionen, wie z.B. die Wertschätzung gegenüber anderer Teammitglieder, zeigen, werden andere Teammitglieder im weiteren Verlauf der Teamarbeit ermutigt, Wissen mit anderen Teammitgliedern zu teilen und gemeinsam zu reflektieren. (4) Wenn Teammitglieder negative emotionale Reaktionen, wie Frustration oder Antagonismus zeigen, werden andere Teammitglieder daran gehemmt, im weiteren Verlauf der Teamarbeit Wissen zu teilen. (5) Wenn Teammitglieder von Beginn der Teamarbeit an, gemeinsamen reflektieren, werden andere Teammitglieder beeinflusst, im weiteren Verlauf der Teamarbeit mehr positive und weniger negative emotionale Reaktionen zu zeigen. Auf Basis der Erkenntnisse der empirischen Studien, wurde die Empfehlung ausgesprochen, dass bei der Untersuchung von Teamlernen in der Teamarbeit, insbesondere unter Berücksichtigung von Emotionen, vor allem die interpersonelle Ebene im Vordergrund stehen sollte. Insbesondere liefert die vorliegende Dissertation für die bestehende Literatur zum Forschungsfeld Teamlernen und Emotionen folgende konkrete Erkenntnisse: (1) Anhand der Verwendung von mixed-methods konnte ein vertiefender Einblick in die Verbindung zwischen Teamlernen und Emotionen in der Teamarbeit am Arbeitsplatz gegeben werden. (2) Hinsichtlich der Rolle von Emotionen beim Teamlernen konnten Verbindungen zwischen positiven oder negativen Emotionen (als Erfahrungen und als Reaktionen) und Teamlernaktivitäten während der Teamarbeit auf der individuellen, der interpersonellen und der Teamebene gefunden werden. Die vorliegende Dissertation hat verschiedene Limitationen vorzuweisen, welche am Ende genannt und mit Empfehlungen für die zukünftige Forschung verknüpft wurden. Diese Dissertation schließt ab mit praktischen Empfehlungen für Personen, die Teil eines Arbeitsteams sind, insbesondere eines interdisziplinären Arbeitsteams an beruflichen Schulen. Die Teammitglieder sollen sich ermutigt fühlen und dabei unterstützt werden, positive emotionale Reaktionen in der Teamarbeit zu zeigen und offen über Emotionen zu sprechen sowie die Teamlernaktivitäten von Beginn der Teamarbeit an auszuführen, um die Teamarbeit nachhaltig zu verbessern

Development of an in vitro model on cellular adhesion on granular natural bone mineral under dynamic seeding condition- A pilot study

Adhesion of osteogenic cells on biomaterials can be studied with static in vitro models, whereas models representing dynamic seeding conditions are rare. Herein, we present an in vitro model to study cell adhesion on granular biomaterials under dynamic seeding conditions. Radiolabeled osteogenic MC3T3-E1 cells were allowed to adhere to granules of natural bovine bone mineral (NBM) under constant rotation. Adhesion of MC3T3-E1 cells was determined by liquid scintillation counting, and cell morphology was visualized by scanning electron microscopy. Cell viability was determined by MTT assay under static and dynamic conditions, at room and body temperature, and in the presence or absence of serum. We show here that MC3T3-E1 cells rapidly adhere to NBM, reaching a peak 3 h after seeding. Attached cells display characteristic signs of spreading. Five to ten percent of total radioactivity remained on NBM after the removal of nonadherent cells. Viability is maintained at room temperature and under rotation for upto 3 h. This data suggests that the dynamic in vitro model presented here provides a tool to study cell adhesion on granular biomaterial

Effectiveness and economic evaluation of therapeutic Nordic walking in patients with psychosomatic disorders: A pragmatic randomized controlled trial.

The effects of exercise therapy in patients with psychosomatic disorders are modest. Therapeutic Nordic walking (tNW) might be a clinically meaningful and cost-effective additional treatment modality. This study aimed to investigate the effects of a tNW program on improving coping ability, compared to the usual care in highly disabled patients with diverse psychosomatic disorders in a hospital setting, and the willingness-to-pay for this treatment modality. Primary outcomes were self-efficacy, readiness to change health behavior, physical performance and attitude to walking. Economic evaluation was conducted with the willingness-to-pay questionnaire. Cohens’ d and 95% confidence intervals were calculated for baseline, discharge and three month follow up using intention-to-treat analysis. Differences between groups were tested by t-test or nonparametric ANOVA. A total of 150 patients were included in this study. Results show no significant differences between the experimental and control group for any of the outcomes. Ratings of stages of change within the transtheoretical model were made by therapists or patients, they showed small effects within both groups (precontemplation: 0.2-0.4 points; preparation: 0.1-0.2; action: 0.4-1.1; maintenance: 0.4 for every comparison). There was no additional effect of the tNW program compared to the standard program in the outcome willingness-to-pay for tNW. However, since clinical experience and treatment expectancy of both patients and health care providers with this treatment modality play an important role in the treatment process, tNW might be a low-budget treatment option for some patients

Climatic, social and reproductive influences on behavioural thermoregulation in a female-dominated lemur

It is well-established that social rank in a large group confers a higher adaptive value to a dominant individual relative to others, though there is scant evidence that members of small social groups either have similar social standing or maintain strict dominance. We aimed to determine whether members of small social groups, using the southern bamboo lemur (Hapalemur meridionalis) as a model, gain rank-related benefits. We first established a dominance hierarchy through a network-based analysis of win-loss interactions, which showed that adult females maintained social dominance within their groups, similar to many strepsirrhine species. To address whether dominant individuals gained rank-related benefits, we then explored how social dynamics may permit access to resting huddles, which provide a physiological benefit. Social thermoregulation, i.e. huddling, is a behavioural energy conservation mechanism, and among many mammals is a direct response to decreasing ambient temperatures. As such, huddling behaviour may have evolved among social animals because of its potential direct and indirect benefits. To examine the effect of dominance rank within small social groups on huddling inclusion, we used generalized linear mixed-effects models to predict the likelihood of huddling to occur during resting bouts from climatic (e.g., temperature, precipitation), social (e.g., affiliation, dominance rank, grooming) and reproductive (e.g., access, infant protection) variables. We found that colder temperatures, especially during shorter resting bouts, increased the likelihood of huddling. Grooming between partners with a high discrepancy in rank increased huddling. Additionally, huddling increased during the reproductive season, potentially offering greater opportunity for males to gain favour with sexually receptive females, and also when new-borns were present, providing essential thermal maintenance and potential anti-predator protection to infants. Taken as a whole, our results suggest that even in small social groups, females gain rank-related benefits by controlling access to huddles, i.e., the intrinsic benefits of social thermoregulation

Predator avoidance and dietary fibre predict diurnality in the cathemeral folivore Hapalemur meridionalis

Though numerous mammalian taxa exhibit cathemerality (i.e. activity distributed across the 24-h cycle), this includes very few primates, exceptions being species from Aotinae and Lemuridae. Four non-mutually exclusive hypotheses have been proposed to explain the ultimate determinants for cathemeral activity in lemurs: thermoregulatory benefits, anti-predator strategy, competition avoidance and metabolic dietary-related needs. However, these have only been explored in the frugivorous genus Eulemur, with some species increasing nocturnality as a possible response to avoid diurnal raptors and to increase their ability to digest fibre during resource-scarce periods. Since Eulemur lack specializations for digesting bulk food, this strategy would allow for processing fibres over the full 24-h. The folivorous lemurids, i.e. genus Hapalemur, provide a divergent model to explore these hypotheses due to gastrointestinal adaptations for digesting dietary fibre and small body size compared to Eulemur. We linked continuous activity data collected from archival tags with observational behaviour and feeding data from three groups of adult Hapalemur meridionalis from January to December 2013. We tested the effects of thermoregulation, predator avoidance and the weighted proportion of digestible dietary fibre on the daily diurnal/nocturnal activity ratio using a Linear Mixed-Model. Our best-fit model revealed that increased canopy exposure and dietary fibre predicted greater diurnality. Our findings partly contrast with previous predictions for frugivorous lemurids. We propose a divergent adaptive explanation for folivorous lemurids. We suggest that the need to avoid terrestrial predators, as well as longer digestive bouts during bulk food periods, may override cathemerality in favour of diurnality in these bamboo lemurs

Relevance of Variations in the Opposing Dentition for the Functionality of Fixed and Removable Partial Dentures: A Systematic Review

The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a “biometric quality” tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture