Speaker:

Kristina Lerman, Professor of Informatics, Luddy School of Informatics, Computing and Engineering, Indiana University

Title:

Social Dynamics of Human-Algorithm Interactions Amplify Social Dysfunction

Abstract:

Social media platforms have achieved remarkable success by predicting what users will click, watch, share, and engage with. Yet algorithmic feeds have also been implicated in rising polarization, growing psychological distress, and the erosion of social trust. How can systems so effective at predicting human behavior produce outcomes poorly aligned with human welfare? I introduce algorithmic misalignment as a framework for understanding this puzzle. Recommendation algorithms are optimized to predict observable behavior, but behavioral signals are imperfect proxies for what people actually want or value. Moreover, optimization favors behaviors that are easiest to predict—often fast, reactive, and emotionally driven responses. Feedback loops reinforce these tendencies as algorithmic recommendations shape behavior that subsequently becomes algorithmic training data, allowing subtle human biases to scale into collective outcomes. I illustrate this framework through two case studies. In political discourse, algorithms amplify anger, outrage, and out-group hostility, contributing to affective polarization. Interactions between groups then transform animosity into durable partisan disagreements. In mental health, algorithmic feeds amplify social comparison, envy, and status anxiety, with consequences for body image and eating disorders. Although typically studied separately, these outcomes may share a common structural origin in the interaction between human psychology and algorithmic optimization, suggesting new directions for designing healthier human–algorithm ecosystems.

Speaker Bio:

Kristina Lerman is a Professor of Informatics at Indiana University’s Luddy School of Informatics, Computing and Engineering. Trained as a physicist, she uses AI, machine learning and network science to answer questions in computational social science, including how algorithms and online platforms shape social behavior and human psychology, access to information, attention, and social-emotional support. Her work has been covered by the Washington Post, Wall Street Journal, and The Atlantic. She is a fellow of AAAI.

Location:

In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/93389536671

About the Speaker Series:

Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, networks, and artificial intelligence. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.

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