The Visual Narrative II: Visual Stereotypes & Social Networks – A Field Experiment on Social Media

Last registered on May 13, 2024


Trial Information

General Information

The Visual Narrative II: Visual Stereotypes & Social Networks – A Field Experiment on Social Media
Initial registration date
May 07, 2024

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
May 13, 2024, 12:19 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.



Primary Investigator

University of Tuebingen

Other Primary Investigator(s)

PI Affiliation
University of Tuebingen
PI Affiliation
University of Tuebingen

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
This study conducts a field experiment to investigate the extent of ethnic discrimination in the formation of personal social networks and the role of visual stereotypes. We study the effect of ethnicity on the acceptance rate of friend or follower requests and the extent to which visual stereotypes moderate this effect. Therefore, we use fictitious social media profiles created on the social networking site Instagram with either Turkish- or German-sounding male names and pictures that either signal visual stereotypes, such as religious beliefs and cultural orientation, or do not. The social media profiles are based on previous research (AEARCTR-0011322) in which we conducted a field experiment in the market for shared housing to investigate the effect of ethnicity and visual stereotypes on the probability of receiving an invitation to view a room in a shared apartment and meet potential roommates. In this follow-up experiment, we aim to investigate a potential determinant of ethnic discrimination: the formation of personal social networks, which may indicate an initial hurdle to integration in housing and other markets. Therefore, we collect suggestions for friends or contacts to follow made by the social networking platform. We then send friend or follower requests to these users and measure the rate of acceptance. Additionally, we observe whether users re-follow the fictitious profile to shed light on ethnic discrimination in personal social network formation and the role of visual stereotypes.
External Link(s)

Registration Citation

Manger, Christian, Raphael Moritz and Kerstin Pull. 2024. "The Visual Narrative II: Visual Stereotypes & Social Networks – A Field Experiment on Social Media." AEA RCT Registry. May 13.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Acceptance rate
Primary Outcomes (explanation)
Acceptance rate conditional on variation in social media information signaling ethnicity and visual stereotypes. The acceptance rate measures whether a user accepts the friend/follow request (in case of a private profile) and/or whether a user re-follows the fictitious profile that sent the request (in case of private and/or public profiles).

Secondary Outcomes

Secondary Outcomes (end points)
Profile visits, impressions, and reach of profiles/posts
Secondary Outcomes (explanation)
Profile visits, reach, and impressions of profiles and/or posts are measured on an aggregated level using the data provided on the platform.

Experimental Design

Experimental Design
To examine the effect of ethnicity and visual stereotypes on the formation of personal social networks, we use four fictitious Instagram profiles. These profiles were created for a randomized controlled trial (AEARCTR-0011322) that conducted a correspondence test in the shared housing market. Half of the fictitious social media profiles contain photos that refer to common Turkish stereotypes in addition to general, non-ethnically specific images. Further, half of the profiles feature a German-sounding male name, while the other half features a Turkish-sounding male name. The present study aims to measure the rate of acceptance of friend/follower requests on social networking sites using these fictitious profiles. The study will use the 'discover friends' suggestions made by the SNS. We collect friend/contact suggestions from the social networking site (180 to 325 per profile in order to achieve a power of .95; see section “Sample size by treatment arms” below) and send a request to follow these profiles. These suggestions are primarily based on existing networks, resulting in a subject pool of students that closely resembles the subject pool of the RCT (AEARCTR-0011322). In cases where a subject is suggested more than once, we randomly select one of the corresponding fictitious profiles to send a friend/follow request to the respective user. Data is collected on the decision of subjects regarding contact requests, including accept or decline (in case of private profiles), or re-follow (in case of private and/or public profiles). Additionally, we collect data on the degree of connection between a person and our profiles, as measured by the number of connections with a suggested profile. Furthermore, we collect publicly available data on target profiles, such as gender, number of contacts, posts, and biographical information.
Experimental Design Details
Not available
Randomization Method
n/a; the sample is rather “ad hoc” (convenience sample) since we do not know how the algorithm of the social networking site composes the suggestions. If a profile suggests the same user as a follower or friend as another profile, the user will be randomly selected to be contacted by one of the corresponding fictitious profiles.
Randomization Unit
Individual level (if applicable, see above)
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
The study uses two by two = four profiles (two using a German-, two a Turkish-sounding male name, two feature visual Turkish stereotypes, two lack Turkish stereotypical images). A small feasibility test of the experimental design was conducted, albeit without varying ethnicity and visual stereotypes. Therefore, it is difficult to estimate a realistic minimum detectable effect size. Given these constraints, we estimate that we need approximately 180-325 subjects for friend/follow requests per condition to achieve a power of .95 (depending on effect size). Additionally, depending on the contact suggestions provided by the platform, we may require slightly more observations to ensure sufficient variation in the ‘closeness’ of the suggested contacts, thus preventing subjects from becoming aware of the experiment.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ethics Committee of the Faculty of Economics and Social Sciences of the Eberhard Karls University Tübingen
IRB Approval Date
IRB Approval Number