Profile pictures for experiment on religious hiring discrimination

Participants evaluate a set of fictitious profile photographs on perceived ethnic origin and physical attractiveness that will be used in a later factorial survey experiment on hiring decisions. Each respondent is randomly shown 12 photographs drawn from a universe of 48 photographs.

The photographs depict individuals intended to represent ethnically ambiguous candidates between West-European and minority origins. The full set contains four categories (12 photographs each):
- Ethnically ambiguous men (Maghrebi–West European)
- Ethnically ambiguous women (Maghrebi–West European)
- Ethnically ambiguous men (Eastern European–West European)
- Ethnically ambiguous women (Eastern European–West European)

The photo pretest serves to validate the stimuli used in a factorial vignette experiment on hiring discrimination related to religious identity.

A total of 48 candidate photographs are pretested. Respondents (HR professionals) each evaluate 12 randomly selected photographs. For each photo, they assess the perceived probability that the person is of a given ethnic origin (Maghrebi/Eastern European vs West European) on a 0–10 Likert scale, as well as perceived attractiveness.

Because it proved infeasible to identify a sufficient number of photographs within each category that were statistically equivalent within a ±0.5 margin around the midpoint of the ethnic ambiguity scale, the final selection procedure prioritizes photographs whose mean perceived ethnic origin is as close as possible to the midpoint of 5. The number of photographs selected per category (female Eastern European ambiguous, male Eastern European ambiguous, female Maghrebi ambiguous, male Maghrebi ambiguous) is determined by the requirement that each experimental deck in the main factorial survey contains only unique photographs, thereby increasing realism for respondents. In the main experiment, photograph fixed effects will be included in all regression analyses to control for all photograph characteristics, including perceived ethnicity and physical attractiveness.

2026-03-16

2026-03-31

- Perceived ethnic ambiguity (Maghrebi/Eastern European or Western European)
- Perceived attractiveness

Photographs are selected based on proximity to the midpoint (5) on the 0–10 scale. Any remaining differences between photographs are accounted for in the main factorial survey experiment by including photograph fixed effects in the statistical analyses.

Perceived physical attractiveness of the photographed individual, measured on an 11-point Likert scale (0–10).

For each photograph, the mean attractiveness score will be calculated across respondents.

This study is a randomized photo evaluation survey. A total of 48 candidate photographs are available. Each respondent evaluates 12 photographs randomly drawn without replacement from the full set.

Participants rate each photograph on:
- perceived ethnic origin;
- perceived physical attractiveness.

Respondents are HR professionals recruited through a research agency.

Participation requires informed consent and agreement with GDPR guidelines. An attention check is included in the survey. Respondents who fail the attention check or who do not provide consent are excluded.

The goal of the study is to identify ethnically ambiguous photographs for use in a subsequent factorial vignette experiment on hiring decisions.

Randomization is conducted automatically by the survey software (Qualtrics) using a computer-generated random assignment. Each respondent receives 12 photographs randomly selected from the set of 48 photographs.

The individual respondent.

Photograph assignment occurs at the photo level within respondents, meaning each respondent evaluates a randomized subset of the available photographs.

No

Not applicable (no clusters).

140 respondents (HR professionals). Each respondent evaluates 12 photographs, resulting in approximately 1,680 photo evaluations.

Not applicable.