Matthew Leitao, behavioral scientist

People trust AI less than doctors, even when the advice is identical.

I design experiments on how people decide whether to trust AI, then report what the data support, including the null results. I am a postdoctoral researcher at the National Institutes of Health.

See the evidence Browse my skills

I turn questions about people and AI into evidence

I am a behavioral scientist with a PhD in psychology from Georgetown and a master's in public policy. I study how people trust, interpret, and make decisions with AI, especially in health. At the National Human Genome Research Institute, I study how people read AI-generated health information, how uncertainty changes trust, and how virtual reality can fit into clinical research.

My dissertation ran six experiments with more than 3,000 people. I build the study, analyze the data in R, and explain the result in plain words. I have also led teams of up to 15 and managed six concurrent projects.

What I do

  • Design experiments

    Randomized studies, registered in advance, from the first hypothesis through recruitment, analysis, and write-up.

  • Model messy human data

    Multilevel, longitudinal, and causal models in R, applied to surveys, daily diaries, and clinical-trial data.

  • Lead research teams

    I managed five research assistants across six or seven projects at Georgetown. I now manage six projects at NIH.

  • Build with AI

    I build research tools on LLM APIs, test AI output with blind ratings, and use AI to speed up analysis and code.

Where I have expertise

  • Trust in AI and algorithms
  • Human-AI collaboration at work
  • Anthropomorphism and mind perception
  • Medical AI and health decisions
  • Genetic risk and health beliefs
  • Digital health behavior change
  • Psychology of technology
  • Smartphones and wellbeing
  • Virtual reality in research
  • Clinical drug trials, behavioral outcomes
  • COVID-19 and social behavior
  • Parasocial relationships
  • Gaming and motivation
  • Obedience to authority
  • Open science and reproducibility

See the work behind each topic

The gap shows up in every kind of medical decision

In Study 2 of my dissertation, 106 adults rated how much they trusted a doctor and an AI making the same medical judgment. Each dot is the average difference, and the line is its 95% confidence interval. Hover over a row or tab to it for the exact statistics.

Physical health 3.98 [3.40, 4.57] Mental health 3.91 [3.30, 4.53] Bodily injury 3.97 [3.38, 4.56] Acute sickness 3.93 [3.33, 4.54] Chronic sickness 4.00 [3.40, 4.60] -1012345 Doctor minus AI, in trust rating points

AI trusted more Doctor trusted more

View as a table
Domain Difference 95% CI t df Cohen's d
Physical health 3.98 3.40 to 4.57 13.55 103 1.33
Mental health 3.91 3.30 to 4.53 12.67 103 1.24
Bodily injury 3.97 3.38 to 4.56 13.32 103 1.31
Acute sickness 3.93 3.33 to 4.54 12.85 104 1.25
Chronic sickness 4.00 3.40 to 4.60 13.2 104 1.29

The gap is large in all five domains, with effect sizes from d = 1.24 to 1.33. It barely moves with the type of decision, so the cause is more likely in how people see the decision-maker than in the medical content. The rest of the dissertation tests that idea.

Source: Leitao (2024), Georgetown University dissertation, Study 2, Table 7. Read the full case study.

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