Script from: The marginal majority effect: when social influence produces lock-in

People are influenced by the choices of others, a phenomenon observed across contexts in the social and behavioral sciences. Social influence can lock in an initial popularity advantage of an option over a higher quality alternative. Yet, several experiments designed to enable social influence have found that social systems self-correct rather than lock in. Here, we identify a behavioral phenomenon that makes inferior lock-in possible, which we call the 'marginal majority effect': A discontinuous increase in the choice probability of an option as its popularity exceeds that of a competing option. We demonstrate the existence of a marginal majority effect in several recent experiments and show that lock-in always occurs when the effect is large enough to offset the quality effect on choice, but rarely otherwise. Our results reconcile conflicting past empirical evidence and connect a behavioral phenomenon to the possibility of social lock-in.
, , # Script from: The marginal majority effect: when social influence produces lock-in

Dataset DOI: [10.5061/dryad.dr7sqvb8q](10.5061/dryad.dr7sqvb8q)

## Description of the data and file structure

#### File: main.py

**Description:** This is the code used to generate figures 4 and 6-9 in the paper \"The marginal majority effect: when social influence produces lock-in\", as well as supplementary figures S2-S13. It also performs the statistical analyses reported in both the main paper an the supplementary material. It has been tested in Python 3.13 with the following package versions:

matplotlib 3.10.7

pandas 2.3.3

scipy 1.16.2

seaborn 0.13.2

statsmodels 0.14.5

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### How to run the code

To reproduce the figures and statistical analyses, first download the data from the experiments analyzed:

\- V2019: [https://doi.org/10.17605/osf.io/p4y37](https://doi.org/10.17605/osf.io/p4y37), specifically the file vanderijt2019.csv

\- MDRT2019: [https://doi.org/10.5281/zenodo.17455649](htt...,