177,837 research outputs found
Information search in experience-based choice and valuation : challenges and applications
Full text linkHow people learn about options may play a more important role than their preferences in
determining their choice. This is the bottom line of a 10-year-old research program on the gap
between experience- and description-based choice. In this dissertation, I continue this line of
research by studying the underlying mechanisms and applying existing knowledge to decision
environments in the real world. Paper 1 evaluates the role of recency in the description‒
experience gap and concludes that it can be traced back to active search strategies, rather than
to memory limitations. Paper 2 expands the investigation of recency, showing that its very
cause—self-terminated search—poses severe methodological challenges to the study of
recency and experience in general. Paper 3 presents evidence for an intricate connection
between the length of active information search and preferences, which not only substantiates
the claims of the first two papers, but also introduces yet another challenge for the study of
experience-based choice. Namely, when a person’s preference determines her information
search, the length and outcome of her search may be more indicative of her preference than
the choice itself. Taking a much broader perspective, in papers 4 and 5 I apply the knowledge
obtained on the description‒experience gap to realistic choice environments. Representing a
proof of concept, Paper 4 establishes a connection between the description‒experience gap
and online consumer choices based on different formats of consumer reviews. Paper 5
extends this work by discussing the potential merits of experience-based information formats
for private and corporate risky choices and highlights the need to better understand the often
intricate relationships between experience and description in real-life choice situations
Frey, Pedroni, Mata, Rieskamp, and Hertwig (2017)
No full textThese are the R-scripts for the analyses reported in Frey, Pedroni, Mata, Rieskamp, and Hertwig (2017). Too see the full dataset of the Basel-Berlin Risk Study, please click on "The Basel-Berlin Risk Study" above
Lejarraga, Frey, Schnitzlein, and Hertwig (2019)
No full textThese are the R-scripts for the analyses reported in Lejarraga, Frey, Schnitzlein, and Hertwig (2019). Too see the full dataset of the Basel-Berlin Risk Study, please click on "The Basel-Berlin Risk Study" above
Lejarraga, Frey, Schnitzlein, and Hertwig (2019)
No full textThese are the R-scripts for the analyses reported in Lejarraga, Frey, Schnitzlein, and Hertwig (2019). Too see the full dataset of the Basel-Berlin Risk Study, please click on "The Basel-Berlin Risk Study" above
The life span development of decision making
Full text linkDie vorliegende Dissertation setzt sich mit der Lebensspannenentwicklung von Entscheidungsverhalten auseinander. Sie beschäftigt sich insbesondere damit, wie sich das Zusammenspiel von Umwelt und Kognition auf Entscheidungen auswirkt, wenn Personen älter werden. Dabei liegt ein Schwerpunkt auf der Lebensspannenentwicklung der Bereitschaft Risiken einzugehen (drei Manuskripte) und ein weiterer darauf, zu untersuchen, wie sich steigende kognitive Anforderungen beim Treffen von Entscheidungen auf Altersunterschiede der Entscheidungsqualität auswirken (ein Manuskript). Im ersten Manuskript, „Stability and change in risk-taking propensity across the adult lifespan“ wird anhand eines repräsentativen Längsschnittdatensatzes untersucht, wie sich die Bereitschaft Risiken einzugehen in Abhängigkeit des Lebensbereiches und über die Lebensspanne verändert. Die Resultate zeigen, dass die Risikobereitschaft Charakteristika ähnlich zu denen eines Persönlichkeitsmerkmals aufweist: Am unteren und oberen Ende der Lebensspanne ist die individuelle Stabilität über die Zeit hinweg im Vergleich zum mittleren Alter am geringsten. Die Risikobereitschaft nimmt im Mittel jedoch ab und diese Abnahme ist nicht in jedem Lebensbereich gleich. Die individuelle Veränderung der Risikobereitschaft über die Zeit steht mit individuellen Veränderungen anderer Persönlichkeitsmerkmale wie Extraversion und Offenheit für Erfahrungen in Zusammenhang. Das zweite Manuskript „Age differences in risk-taking propensity are related to perceptions of risk and reward but not perceived control“ untersucht mögliche psychologische Mechanismen hinter der alters- und bereichsspezifischen Veränderung der Risikobereitschaft. Anhand eines weiteren repräsentativen Datensatzes wird analysiert, in wie weit altersbedingte Veränderungen in der Wahrnehmung von Risiko, Nutzen, und Kontrolle in verschiedenen Lebensbereichen eine Rolle spielen. Die Resultate zeigen, dass eine veränderte Wahrnehmung von Kosten und Nutzen die Veränderungen erklären können, nicht jedoch eine veränderte Kontrollwahrnehmung. Das dritte Manuskript „Propensity for risk taking across the life span and around the globe“ untersucht, ob die generelle mittlere Abnahme der Risikobereitschaft für Menschen auf der ganzen Welt gültig ist. Die Annahme ist, dass Merkmale wie Armut, Mordrate, und Einkommensungleichheit Einfluss auf die individuelle Risikobereitschaft nehmen, weil Menschen, in Ländern in denen Ressourcen knapp sind, stärker miteinander konkurrieren müssen als Menschen in Ländern, in denen dies nicht der Fall ist. Die Ergebnisse zeigen einen deutlichen Zusammenhang zwischen der Situation in einem Land und der Abnahme der Risikoneigung über die Lebensspanne.
Das vierte Manuskript „How cognitive aging affects decision making under increased memory demands“ untersucht, wie sich steigende kognitive Anforderungen beim Treffen von Entscheidungen auf Altersunterschiede in der Entscheidungsqualität und die Strategieselektion auswirken. Gedächtnisfähigkeiten unterliegen einer stetigen Veränderung über die Lebensspanne und insbesondere ältere Personen zeigen Defizite in der Erinnerungsleistung. Die Ergebnisse zeigen, dass mit zunehmenden Gedächtnisanforderungen, Altersunterschiede in der Entscheidungsqualität größer werden. Individuelle Gedächtnisfähigkeiten mediierten diesen Zusammenhang. Die Ergebnisse sind zudem dadurch zu erklären, dass ältere Erwachsene im Vergleich zu jüngeren Erwachsenen in geringerem Maße zu kompensatorischen Entscheidungsstrategien wählen.
Insgesamt unterstreichen die Ergebnisse dieser Dissertation, dass für die Untersuchung von Phänomenen menschlicher Entwicklung das Zusammenspiel von Mensch und Umwelt berücksichtigt werden muss. Diese Dissertation zeigt, dass Veränderungen dieser Phänomene, wie zum Beispiel menschliches Entscheidungsverhalten, oft eine Anpassungsleistungen des Menschen an unterschiedliche Lebensbereiche, kulturelle Umwelten, oder an eine sich verändernde kognitive Leistungsfähigkeit sind.
Abstract
Individuals of all ages are often confronted with situations varying in their complexity and situational characteristics. Normal aging is associated with changes in cognitive capacities such as learning and memory but also notable alterations in physical fitness, health, and the social environment. These changes most likely affect not only the necessary cognitive tools but also the perception of gains and losses in relation to available resources and personal goals when making decisions. This dissertation shows that age differences in decision making cannot be understood without considering the fit between the individual resources and the characteristics of the choice environment. It comprises three papers studying the effect of aging on the propensity to take risks as well as one paper on inference decisions in choice ecologies that differ in memory demand.
The first paper investigates longitudinal changes in risk-taking propensity across the life span. It shows that the propensity to take risks varies as a function of age and domain. Interestingly, different conceptions of change suggest that risk-taking propensity has trait-like properties similar to those found in major personality traits such as the Big Five. The second paper studies the psychological mechanisms of age- and domain-differences in risk-taking propensity. It finds that individual differences in the perceptions of costs and benefits, but not control beliefs, account for the prominent age-related but domain-variant change in risk-taking propensity. The third paper presents a cross-cultural investigation of life span changes in risk-taking propensity. It suggests that age-related changes in risk taking are associated with local characteristics: Countries in which hardship (i.e., homicide rate, gross domestic product, income/gender inequality) is largest show least changes in risk-taking propensity over the life span. Finally, the fourth paper summarizes empirical studies on the effects of memory demand on age differences in inference decisions. It displays that individual memory ability is crucial for the maintenance of adequate decision outcomes in choice environments that pose high demands on memory. Overall, these findings emphasize that in order to predict life span changes in decision making, one needs to take the interaction between the individual and the environment into account. Developmental phenomena such as changes in decision making can be understood as individual efforts to adapt one’s performance to both internal and external changes such as in the environment surrounding them or their own motivations and cognitive capacity
Zellen- und gewebelehre, morphologie und entwicklungsgeschichte
No full text"Literatur" at end of each article.Die einzelligen organismen, von R. Hertwig.--Zellen und gewebe des tierkörpers, von H. Poll.--Allgemeine und experimentelle morphologie und entwicklungs lehre der tiere, von O. Hertwig.--Entwicklungsgeschichte und morphologie der wirbellosen, von K. Heider.--Die entwicklungsgeschichte der wirbeltiere, von F. Keibel.--Morphologie der wirbeltiere, von E. Gaupp.--Register, von E. Schroeder.Mode of access: Internet
Simple heuristics in a social game
Full text linkSimple Heuristics in a Social World invites readers to discover the simple heuristics that people use to navigate the complexities and surprises of environments populated with others. The social world is a terrain where humans and other animals compete with conspecifics for myriad resources, including food, mates, and status, and where rivals grant the decision maker little time for deep thought, protracted information search, or complex calculations. Yet, the social world also encompasses domains where social animals such as humans can learn from one another and can forge alliances with one another to boost their chances of success.
According to the book's thesis, the undeniable complexity of the social world does not dictate cognitive complexity as many scholars of rationality argue. Rather, it entails circumstances that render optimization impossible or computationally arduous: intractability, the existence of incommensurable considerations, and competing goals. With optimization beyond reach, less can be more. That is, heuristics--simple strategies for making decisions when time is pressing and careful deliberation an unaffordable luxury--become indispensible mental tools. As accurate as or even more accurate than complex methods when used in the appropriate social environments, these heuristics are good descriptive models of how people make many decisions and inferences, but their impressive performance also poses a normative challenge for optimization models. In short, the Homo socialis may prove to be a Homo heuristicus whose intelligence reflects ecological rather than logical rationality
Simple heuristics: The foundations of adaptive social behavior
Full text linkThis chapter shows how simple heuristics can be an essential tool for navigating the complexities and vagaries of social environments. The research program on the nature of social rationality presented here can be summarized by the following theses: As perceived by the human mind, the social world (Umwelt) is complex, but not necessarily more complex than the nonsocial world. However complex the social world may be, its complexity does not require cognitive complexity; rather, it entails conditions that make simple heuristics indispensible, such as intractability, multiple competing goals, and incommensurable reasons. Much of reasoning and decision making occurring in human and animal social environments can be modeled in terms of simple heuristics. Although simple heuristics forgo extensive information search and complex calculations, they can be as accurate and even more accurate than more complex strategies and/or can be used to reach other goals that are valued in social environments (e.g., transparency, fairness, speed). Heuristics can be simultaneously successful and simple by coopting evolved capacities. The capacities themselves can represent complex adaptive specializations (e.g., memory, movement tracking). Simple heuristics per se are neither rational nor irrational. Their rationality is ecological. That is, their performance depends on the match between the architecture of the heuristic and the structure of the environment in which it is used. The heuristics' simplicity inoculates them against overfitting and enables them to achieve robust performance given small samples of information. Simple heuristics can model adaptive decision making both in games against nature and in social games. There is no social intelligence distinct from nonsocial intelligence. Simple heuristics are tools of moderate generalizability. Some can be used only in games against nature, whereas others are restricted to social games. Still other heuristics can be applied in both types of games. Shedding light on the adaptive toolbox of simple heuristics used to navigate social environments, and characterizing their strengths and weaknesses, can help us design environments and/or heuristics in ways that improve public welfare
Ophidiomyces ophiodiicola, Etiologic Agent of Snake Fungal Disease, in Europe since Late 1950s
No full textThe fungus Ophidiomyces ophiodiicola is the etiologic agent of snake fungal disease. Recent findings date US occurrence at least as far back as 1945. We analyzed 22 free-ranging snakes with gross lesions consistent with snake fungal disease from museum collections from Europe. We found 5 positive samples, the oldest collected in 1959
Adaptive information search and judgment strategies in solitary and competitive tasks
Full text linkA substantial body of judgment and decision-making research focuses on decisions made under risk, where all relevant option outcome and probability information is known a priori. However, most real-world decision tasks are made under uncertainty, where such population- level information is unknown. Against this background, how can, do, and should organisms obtain and use information in order to improve their judgments and decisions under uncertainty? This dissertation addresses these questions in two distinct domains: external information search in competitive tasks (papers 1 and 2) and internal search in the context of the inner-crowd (papers 3 and 4). In paper 1, we develop a new paradigm called the Competitive Sampling Game (CSG) to study how organisms adjust search in the presence of both natural uncertainty (i.e., gamble parameters) and social uncertainty (i.e., behavior of others). The paradigm produces simulation and empirical results showing that organisms should and do dramatically reduce search in the presence of competition to almost minimal levels. In paper 2, we expand on the initial results of the CSG to show how different levels of competition drive the evolution of decision strategies. In a second domain, we address how people can improve their judgments by harnessing a diverse inner-crowd using dialectical bootstrapping. In paper 3, we apply dialectical bootstrapping to a Bayesian reasoning paradigm to show how dialectical instructions induce strategy change and how people can become more Bayesian by averaging biased non-Bayesian judgments in their inner-crowd. In paper 4, we apply the inner-crowd to a cue-based estimation task and model the effects of different estimation strategies on final estimates and confidence. Our results suggest that people can use their confidence judgments to outperform the simple average of their inner-crowd. Moreover, dialectical bootstrapping increases these effects
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