Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 1 / 50 What is Sociology? What is Sociology? Mathematical Sociology, Agent-Based Modeling and Artificial Societies Dirk Helbing and Research Team Chair of Sociology, in particular of Modeling and Simulation Septemer 22, 2008 Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 1 / 50 What is Sociology? What is Sociology? What is Sociology? Sociology focusses on such phenomena as interactions and exchanges between individuals at the “micro-level”, and group dynamics, group development, and crowds at the “macro-level”. Sociologists are interested in the individual, but primarily within the context of larger social structures and processes, such as social roles, race and class, and socialization. They use a combination of qualitative research designs and highly quantitative methods, such as procedures for sampling and surveys. Sociologists in this area are interested in a variety of demographic, social, and cultural phenomena. Some of their major research fields are the emergence of cooperation, social inequality, deviance, conflicts, and social change, norms, roles and socialization. Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 2 / 50 Theoretical Approach Auguste Comte Theoretical Approach Auguste Comte (1798–1857) is the “father” of sociology and proposed a rational (“positivistic”) approach to the study of society, based on observation and experiment. As key concepts he distinguished social statics (social institutions and their relationships, ...) and social dynamics (processes of social change as “natural” breakdowns and rearrangements of social structures). In the beginning, he called his approach “social physics”, but later he used the term “sociology” (meaning knowledge of society). He considered sociology to be the queen of sciences. His approach should also provide a practical basis on which to create a better society, e.g. more stable social order. Source: Smelser Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 3 / 50 Theoretical Approach Max Weber Max Weber (1864–1920) proposed to elaborate “ideal types” as abstract statements of the essential, though often exaggerated characteristics of social phenomena, in order to sharpen comparisons. For example, he explored religions by contrasting the ‘ideal Protestant’ with the ‘ideal Jew’, ‘ideal Hindu’, and ‘ideal Buddhist’, knowing that these models did not precisely descibe any actual individuals. The ideal types serve to be contrasted with the actual, empirical reality. “Ideal” in this context, by the way, does not mean “good” or “best”, but something like “stylized” or “abstracted”. Weber also advocated to become involved in politics outside the classroom, while striving for scientific neutrality in the professional/scientific work. Source: Macionis and Plummer Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 4 / 50 Theoretical Approach Talcott Parsons Talcott Parsons (1902–1979) advocated using “analytical realisms” to build sociological theory. Theory in sociology should be a generalized, coherent system of abstract concepts, which do not correspond to concrete phenomena, but reflect the important features of the social world without being overwhelmed by empirical details. That is, concepts should abstract from empirical reality (with all its diversity and confusion) common analytical elements, in order to isolate phenomena from their embeddedness in the complex relations constituting social reality. Initially, an elaborate classification and categorization of social phenomena is needed that reflects significant features of social phenomena. Source: Turner Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 5 / 50 Organisation of this Course Table of Content Organisation of this Course 1 22. Sept.: Cognitive Dissonance/Decision Making (Dirk Helbing) 2 29. Sept.: Social Segregation (Wenjian Yu) 3 06. Okt.: Social Inequality (Sergi Lozano) 4 13. Okt.: Game Theory and Social Cooperation (Heiko Rauhut) 5 20. Okt.: Friendship Network Formation (Albert Diaz-Guilera) 6 27. Okt.: Group Dynamics (Sergi Rauhut) 7 3. Nov.: Crowd Behavior (Anders Johansson) 8 10. Nov.: Market Dynamics (Albert Diaz-Guilera) 9 17. Nov.: Conflicts, Wars and Violence (Lubos Buzna) 10 24. Nov.: Deviance and Crime (Heiko Rauhut) 11 1. Dez.: Innovation Dynamics (Albert Diaz-Guilera) 12 8. Dez.: Emergence of Conventions and Norms (Dirk Helbing) 13 15. Dez.: Language and Culture, afterwards Exam (Albert Diaz-Guilera) Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 6 / 50 Organisation of this Course Table of Content Chapter 1 Cognitive Dissonance and Decision Making Dirk Helbing www.soms.ethz.ch [email protected] Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 7 / 50 Modeling Behavior Introductory Remark Modeling Behavior A good predictor for future behavior is past behavior. However, attempts to describe human behavior as behavioral responses to environmental stimuli had different degrees of success. The possibility to condition reflexes encouraged the mechanistic idea of a deterministic stimulus-response relationship (inspired by physics and biology). However, the description of reasoned or planned action turned out to be more complicated (requiring to distinguish voluntary behavior from the previously mentioned kinds of behavior). The related stimulus-response theories are based on the concept of attitude and had to be more and more generalized. Source of the following transparencies, if not otherwise stated: Fishbein/Ajzen Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 8 / 50 Modeling Behavior Classical Conditioning Classical Conditioning Paradigm (Pavlov, 1890s) Unconditioned Stimulus (UCS) Unconditioned Response (UCR) Conditioned Stimulus (CS) Conditioned Response (CR) When the UCS preceeds the CS, little learning is observed; the strongest learning effect occurs when the CS precedes the UCS by a short time interval such as 0.5 seconds (causality matters). Food and drinks, e.g., are primary reinforcers, conditioned stimuli are secondary reinforcers. Classical Conditioning [VIDEO] Smart Cat [VIDEO] Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 9 / 50 Modeling Behavior Operant Conditioning Instrumental or Operant Conditioning (Skinner, 1938) Reinforcement learning Principle of reward and punishment Frequency of reinforcement, temporal relation, and magnitude of feedback are relevant Similar stimuli may cause the same or similar Abbildung: Skinner Box responses (association-based generalization) Operant Conditioning+“Behaviorism”[VIDEO] Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 10 / 50 Modeling Behavior Response Consistency Response Consistency Stimulus-Response Consistency A person consistently performs the same response or set of particular responses in the presence of a given stimulus object. Response-Response Consistency The individual is predisposed toward performing a certain class of behaviors, i.e. the responses elicited by one object are consistent with one another. Evaluative Consistency Knowledge of the person’s attitude does not permit prediction of any specific behavior, but he or she is predisposed to a certain degree of favorability in the behavior toward the stimulus object. Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 11 / 50 Modeling Behavior Theory of Reasoned Action Theory of Reasoned Action 1 Attitude: A person’s favorable or unfavorable evaluation of an object → emotions, affect 2 Belief: The cognitive information (opinion) one has about an object → view/interpretation of the world 3 Behavioral Intention: The person’s likelihood to perform the behavior. 4 Behavior: The observable (“overt”) act of the subject. Chair of Sociology, in particular of Modeling and Simulation http://www.soms.ethz.ch/ Mathematical Sociology Dirk Helbing and Research Team Zurich Septemer 22, 2008 12 / 50 Attitudes and Behavior Definitions Attitudes Attitude is viewed as a latent affective variable that guides individual behavior. Attitude may be defined as a 1 learned 2 predisposition 3 to respond in a consistently favorable or unfavorable manner with respect to a given object. One distinguishes 3 types of consistency: 1 stimulus-response consistency 2 response-response consistency 3 evaluative consistency Chair of Sociology, in particular of Modeling and Simulation