In human activities, opinions are everywhere. Politics, prices, religion, even science, all are activities are influenced by them (whether they should be or not is another question entirely).
Part of understanding those problems requires that we have good theoretical models of how we change our minds, by observing others and also by making any general observations about the world. Opinion dynamics is the sub-area of Sociophysics where we study some of those problems.
When can we expect a group to reach consensus?
Is always agreement a good thing?
How extremism can spread in a society?
How can extremism emerge from moderate opinions?
How to counter dangerous extreme points of view?
Opinions and Truth
Social influence can hinder pursuit for truth?
Opinions and fake news
My models, my answers
Emergence of Extremism
By introducing a probabilistic strength to opinions about binary choices, Continuous Opinions and Discrete Actions showed how extremists can appear from simple local reinforcement rules.
How extreme can depend on network structure, external agents, mobility, and other factors.
Supported by: FAPESP Grant 2008/00383-9
Expanding on the theme
Extending CODA allowed the proposal of a general framework for opinion models.
Traditional models can be obtained in limit cases if CODA agents consider their own influence on their neighbors.
A CODA-like version for continuous opinions shows the same behavior as Bounded Confidence models.
Supported by : FAPESP Grants 2008/00383-9 and 2009/08186-0
Communication and Mental Models
What agents expect to conclude can be more important than what is communicated
Estimating trust based on ideological agreement can make a difference
Supported by : FAPESP Grant 2014/00551-0
Trust and network evolution
Trust can destroy tendency to consensus even in a fully connected network and despite its much slower evolution.
Opinions and networks evolve together. Models should reflect that.
Discrete Multiple Options with strength
When there are many independent choices, agent still can have extreme opinions.
Current theoretical models do not agree on how to define extremist opinions. Here is my take on that.