rvenkat + models_of_behavior   14

[1711.04024] How fragile are information cascades?
It is well known that sequential decision making may lead to information cascades. That is, when agents make decisions based on their private information, as well as observing the actions of those before them, then it might be rational to ignore their private signal and imitate the action of previous individuals. If the individuals are choosing between a right and a wrong state, and the initial actions are wrong, then the whole cascade will be wrong. This issue is due to the fact that cascades can be based on very little information.
We show that if agents occasionally disregard the actions of others and base their action only on their private information, then wrong cascades can be avoided. Moreover, we study the optimal asymptotic rate at which the error probability at time t can go to zero. The optimal policy is for the player at time t to follow their private information with probability pt=c/t, leading to a learning rate of c′/t, where the constants c and c′ are explicit.
self_organization  information_diffusion  contagion  decision_making  models_of_behavior  networks  ? 
june 2018 by rvenkat
An Introduction to Model-Based Cognitive Neuroscience | Birte U. Forstmann | Springer
Two recent innovations, the emergence of formal cognitive models and the addition of cognitive neuroscience data to the traditional behavioral data, have resulted in the birth of a new, interdisciplinary field of study: model-based cognitive neuroscience. Despite the increasing scientific interest in model-based cognitive neuroscience, few active researchers and even fewer students have a good knowledge of the two constituent disciplines. The main goal of this edited collection is to promote the integration of cognitive modeling and cognitive neuroscience. Experts in the field will provide tutorial-style chapters that explain particular techniques and highlight their usefulness through concrete examples and numerous case studies. The book will also include a thorough list of references pointing the reader towards additional literature and online resources.
cognition  models_of_behavior  neuroscience  book 
june 2018 by rvenkat
Covering Ground: Movement Patterns and Random Walk Behavior in Aquilonastra anomala Sea Stars | The Biological Bulletin: Vol 231, No 2
The paths animals take while moving through their environments affect their likelihood of encountering food and other resources; thus, models of foraging behavior abound. To collect movement data appropriate for comparison with these models, we used time-lapse photography to track movements of a small, hardy, and easy-to-obtain organism, Aquilonastra anomala sea stars. We recorded the sea stars in a tank over many hours, with and without a food cue. With food present, they covered less distance, as predicted by theory; this strategy would allow them to remain near food. We then compared the paths of the sea stars to three common models of animal movement: Brownian motion, Lévy walks, and correlated random walks; we found that the sea stars’ movements most closely resembled a correlated random walk. Additionally, we compared the search performance of models of Brownian motion, a Lévy walk, and a correlated random walk to that of a model based on the sea stars’ movements. We found that the behavior of the modeled sea star walk was similar to that of the modeled correlated random walk and the Brownian motion model, but that the sea star walk was slightly more likely than the other walks to find targets at intermediate distances. While organisms are unlikely to follow an idealized random walk in all details, our data suggest that comparing the effectiveness of an organism’s paths to those from theory can give insight into the organism’s actual movement strategy. Finally, automated optical tracking of invertebrates proved feasible, and A. anomala was revealed to be a tractable, 2D-movement study system.
models_of_behavior  markov_models  data_analysis 
april 2018 by rvenkat
Comparing the axiomatic and ecological approaches to rationality: fundamental agreement theorems in SCOP | SpringerLink
"There are two prominent viewpoints regarding the nature of rationality and how it should be evaluated in situations of interest: the traditional axiomatic approach and the newer ecological rationality. An obstacle to comparing and evaluating these seemingly opposite approaches is that they employ different language and formalisms, ask different questions, and are at different stages of development. I adapt a formal framework known as SCOP to address this problem by providing a comprehensive common framework in which both approaches may be defined and compared. The main result is that the axiomatic and ecological approaches are in far greater agreement on fundamental issues than has been appreciated; this is supported by a pair of theorems to the effect that they will make accordant rationality judgements when forced to evaluate the same situation. I conclude that ecological rationality has some subtle advantages, but that we should move past the issues currently dominating the discussion of rationality."
rationality  debates  foundations  models_of_behavior  via:cshalizi 
january 2018 by rvenkat
Shared Outrage and Erratic Awards: The Psychology of Punitive Damages | SpringerLink
An experimental study of punitive damage awards in personal injury cases was conducted, using jury-eligible respondents. There was substantial consensus on judgments of the outrageousness of a defendant's actions and of the appropriate severity of punishment. Judgments of dollar awards made by individuals and synthetic juries were much more erratic. These results are familiar characteristics of judgments made on unbounded magnitude scales. The degree of harm suffered by the plaintiff and the size of the firm had a pronounced effect on awards. Some judgmental tasks are far easier than others for juries to perform, and reform possibilities should exploit this fact.


-- use synthetic jury studies to model public opinion?
judgment_decision-making  empirical_legal_studies  law  dmce  teaching  models_of_behavior  moral_psychology  cass.sunstein 
december 2017 by rvenkat
Ten-month-old infants infer the value of goals from the costs of actions | Science
Infants understand that people pursue goals, but how do they learn which goals people prefer? We tested whether infants solve this problem by inverting a mental model of action planning, trading off the costs of acting against the rewards actions bring. After seeing an agent attain two goals equally often at varying costs, infants expected the agent to prefer the goal it attained through costlier actions. These expectations held across three experiments that conveyed cost through different physical path features (height, width, and incline angle), suggesting that an abstract variable—such as “force,” “work,” or “effort”—supported infants’ inferences. We modeled infants’ expectations as Bayesian inferences over utility-theoretic calculations, providing a bridge to recent quantitative accounts of action understanding in older children and adults.
bayesian  cognition  models_of_behavior  cognitive_science  joshua.tenenbaum 
november 2017 by rvenkat
Three-dimensional visualization and a deep-learning model reveal complex fungal parasite networks in behaviorally manipulated ants
Microbial parasites may behave collectively to manipulate their host’s behavior. We examine adaptations of a microbial parasite in its natural environment: the body of its coevolved and manipulated host. Electron microscopy and 3D reconstructions of host and parasite tissues reveal that this fungus invades muscle fibers throughout the ant’s body but leaves the brain intact, and that the fungal cells connect to form extensive networks. The connections are likened to structures that aid in transporting nutrients and organelles in several plant-associated fungi. These findings alter the current view of parasite-extended phenotypes by demonstrating that behavior control does not require the parasite to physically invade the host brain and that parasite cells may coordinate to change host behavior.

--come on guys, your paper is interesting even without the use of _deep learning_ in your title.
evolutionary_biology  embodiement  animal_behavior  via:coyne  models_of_behavior  dmce  teaching  for_friends 
november 2017 by rvenkat
Community and the Crime Decline: The Causal Effect of Local Nonprofits on Violent CrimeAmerican Sociological Review - Patrick Sharkey, Gerard Torrats-Espinosa, Delaram Takyar, 2017
Largely overlooked in the theoretical and empirical literature on the crime decline is a long tradition of research in criminology and urban sociology that considers how violence is regulated through informal sources of social control arising from residents and organizations internal to communities. In this article, we incorporate the “systemic” model of community life into debates on the U.S. crime drop, and we focus on the role that local nonprofit organizations played in the national decline of violence from the 1990s to the 2010s. Using longitudinal data and a strategy to account for the endogeneity of nonprofit formation, we estimate the causal effect on violent crime of nonprofits focused on reducing violence and building stronger communities. Drawing on a panel of 264 cities spanning more than 20 years, we estimate that every 10 additional organizations focusing on crime and community life in a city with 100,000 residents leads to a 9 percent reduction in the murder rate, a 6 percent reduction in the violent crime rate, and a 4 percent reduction in the property crime rate.

a forthcoming book based on this work

and a dilute version here
crime  longitudinal-study  causal_inference  sociology  non-profit  institutions  social_movements  cities  models_of_behavior  book 
november 2017 by rvenkat
Rumor Has It: The Adoption of Unverified Information in Conflict Zones | International Studies Quarterly | Oxford Academic
Rumors run rife in areas affected by political instability and conflict. Their adoption plays a key role in igniting many forms of violence, including riots, ethnic conflict, genocide, and war. While unverified at the time of transmission, some rumors are widely treated as truth, while others are dismissed as implausible or false. What factors lead individuals to embrace rumors and other forms of unverified information? This article presents a new theoretical framework for understanding individual receptivity to rumors and tests it using original survey data gathered in insurgency-affected areas of Thailand and the Philippines. We find wide variation in rumor adoption, and argue that three factors drive individuals to embrace rumors: worldview, threat perception, and prior exposure. Contrary to conventional wisdom, we find no evidence that commonly cited factors—including education, income, age, and gender—determine individual receptivity to rumors. We also explore the implications of belief in rumors on conflict dynamics. We find that greater receptivity to rumors correlates with the belief that ongoing conflict is intractable. This suggests that rumors can not only help spark political violence, but also impede its resolution. Our findings shed light on the complex interaction between worldview and unverified information in shaping popular beliefs—and through them, political contention and competition—in conflict areas and beyond.
public_opinion  common_knowledge  ?  conspiracy_theories  cultural_cognition  dmce  teaching  via:nyhan  models_of_behavior 
october 2017 by rvenkat
Change behaviors by changing perception of normal | Stanford News
-- obviously, one study does not anything but the idea of beliefs about norms and its dynamics are interesting. Political science applications?
norms  social_psychology  influence  social_behavior  dmce  teaching  models_of_behavior 
october 2017 by rvenkat
Attention Manipulation and Information Overload
Limits on consumer attention give firms incentives to manipulate prospective buyers’ allocation of attention. This paper models such attention manipulation and shows that it limits the ability of disclosure regulation to improve consumer welfare. Competitive information supply, from firms competing for attention, can reduce consumers’ knowledge by causing information overload. A single firm subjected to a disclosure mandate may deliberately induce such information overload to obfuscate financially relevant information, or engage in product complexification to bound consumers’ financial literacy. Thus, disclosure rules that would improve welfare for agents without attention limitations can prove ineffective for consumers with limited attention. Obfuscation suggests a role for rules that mandate not only the content but also the format of disclosure; however, even rules that mandate “easy-to-understand” formats can be ineffective against complexification, which may call for regulation of product design.
behavioral_economics  information  rationality  rational_choice  computational_complexity  agency  heuristics  dmce  teaching  models_of_behavior  via:sunstein 
october 2017 by rvenkat

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