Quantifying the effects of social influence

TL;DR

This study quantitatively analyzes how individuals adjust their guesses based on aggregated social information, revealing a linear relationship that is consistent across different questions and levels of information aggregation.

Contribution

It provides the first controlled experimental evidence that individual responses to social influence follow a linear pattern regardless of question difficulty or answer scale.

Findings

Guess adjustments are linearly related to the mean of all guesses.

Individual diversity does not significantly affect social influence response.

Response patterns change with the level of information aggregation.

Abstract

How do humans respond to indirect social influence when making decisions? We analysed an experiment where subjects had to repeatedly guess the correct answer to factual questions, while having only aggregated information about the answers of others. While the response of humans to aggregated information is a widely observed phenomenon, it has not been investigated quantitatively, in a controlled setting. We found that the adjustment of individual guesses depends linearly on the distance to the mean of all guesses. This is a remarkable, and yet surprisingly simple, statistical regularity. It holds across all questions analysed, even though the correct answers differ in several orders of magnitude. Our finding supports the assumption that individual diversity does not affect the response to indirect social influence. It also complements previous results on the nonlinear response in information-rich scenarios. We argue that the nature of the response to social influence crucially changes with the level of information aggregation. This insight contributes to the empirical foundation of models for collective decisions under social influence.