Jose Arellano Martorellet

Research

I study how people engage with health information, and how communication and behavioral interventions change what they do.

Publications

Information Provision and Vaccination Behavior

With Silvia Saccardo and Gretchen B. Chapman

In The SAGE Handbook of Health Psychology (2nd ed., Vol. 2, pp. 433–460). SAGE Publications, 2025.

Evidence synthesis from information provision interventions as a lever for vaccination. Applying a framework based on informational (e.g., risk communication) and non-informational elements (e.g., message source), we evaluate effects on beliefs, attitudes, intentions, and uptake, identify the conditions under which information is more or less likely to change behavior, and outline methodological priorities for future research.

Cover of The SAGE Handbook of Health Psychology

Working papers and research in progress

Under review

Believability of Social Norm Messages and Vaccination Intentions

With Gretchen B. Chapman and Silvia Saccardo

Experiments showing that the effectiveness often credited to injunctive norms and physician endorsement stems partly from something simpler: their claims are easier to believe.

Working paper, 2026

Behaviorally-Enhanced Notification for Patient Portal Messages and Preventive Care Engagement:
A Clinical Trial

With Silvia Saccardo, Jeff Borenstein, Jana Gallus, Craig Fox, Leah Mireles, Suzette Ma,
Jennifer Bocek, Sarah Meshkat, Sitaram Vangala, Jeffrey Fujimoto, and Hengchen Dai

A large-scale randomized controlled trial testing whether behaviorally informed patient communications increase engagement with, and completion of, recommended preventive care.

Working paper, 2026

Improving Parental Emotion Socialization Practices: Effects of a Behavioral Economics-Based Intervention

Magaly S. Noblega, Jose Arellano Martorellet, Katherine Fourment, Olenka Retiz, and Lucía Márquez

Evaluation of a behaviorally informed intervention, delivered through WhatsApp, that supports parental emotion socialization practices among caregivers in Peru.

Manuscript in preparation

Selective (In)attention: Evidence from Healthcare

With Andrea Low, Silvia Saccardo, Hengchen Dai, Craig Fox, Artin Galoosian, Richard Leuchter, Folasade May, Sitaram Vangala, and Jeff Fujimoto

Field and online experiments on how health communications designed to capture patients attention affect their willingness to engage with health information, including cases where interventions discourage rather than encourage engagement.

In progress

Misleading Expertise: Inferring Expertise from Source and Content Cues in Health Communication

With Gretchen B. Chapman and Silvia Saccardo

Experiments examining whether peripheral cues weakly diagnostic of competence, such as professional attire and technical jargon, substitute for credentials in inferences of expertise, and how such cues interact when presented jointly.

In progress

Leveraging the Intention-Action Framework to Close Cardiology Care Gaps

Amber Tang, Hengchen Dai, Jana Gallus, Richard Leuchter, Silvia Saccardo, Jose Arellano Martorellet, Sitaram Vangala, and UCLA Health collaborators

A field experiment testing the separate and joint effects of two behavioral interventions on physicians' actions to close their patients' cardiology care gaps, such as aspirin therapy.

In progress

Strengthening Trust in Climate Scientists: A Megastudy

With Dhwani Yagnaraman, as part of a megastudy led by Jan Pfänder and colleagues

Selected from 107 submissions for a US megastudy on trust in climate scientists, our intervention uses a value-aligned narrative and a delayed reveal to prompt reappraisal of climate scientists.