# Smiling and first impressions in ad hoc entrustment decisions: An avatar-based simulation study

## TL;DR

This study explores how facial expressions affect trust and entrustment decisions in medical scenarios using avatars.

## Contribution

The study introduces avatar-based simulations to investigate the role of facial expressions in ad hoc medical entrustment decisions.

## Key findings

- Trustworthiness was positively linked to entrustment decisions.
- Smiling expressions did not significantly influence entrustment or trustworthiness ratings.
- Context and other first-impression factors may be more important than facial expressions in medical entrustment.

## Abstract

We aimed to examine how neutral and smiling facial expressions, as indicators of non-verbal first impressions, influence ad hoc entrustment and perceptions of trustworthiness in a person in medical scenarios that demand entrustment decisions.

Within the framework of entrustable professional activities (EPA), we tested three hypotheses in an online study using avatar simulations. As a pilot study and for reasons of sample accessibility, 268 medical students (67.2% female) read 36 narrative clinical entrustment situations in a randomized order. The participants then had to decide whether to entrust the clinical task to fellow students who appeared in short videos as standardized avatars. For each scenario, two avatars were presented and randomly matched for different facial expressions (Duchenne smile (DS), neutral), genders, and morphologies. The participants also assessed the avatars’ perceived trustworthiness.

Entrustment and trustworthiness were positively correlated (H1). However, when utilizing mixed-effects models, no significant differences were found between the avatars that displayed a DS and those with a neutral expression regarding positive entrustment decisions (H2) or trustworthiness ratings (H3).

We found that trustworthiness was linked to entrustment, which supports previous findings on trustworthiness as a person-related prerequisite for entrustment decisions. Internalized patterns of the DS did not influence the medical students’ entrustment decisions in the first-impression situations. This suggests that in ad hoc medical entrustment scenarios, factors such as context or other aspects of a trustee’s first impression may shape trustors’ decisions.