do listeners trust accented speech less? what the accent and credibility studies really found

The study

Shiri Lev-Ari and Boaz Keysar, then at the University of Chicago, published Why don't we believe non-native speakers? The influence of accent on credibility in the Journal of Experimental Social Psychology in 2010.

They asked American listeners to judge how true a set of trivia statements were, such as whether a giraffe can go longer without water than a camel. The statements were recorded by native English speakers and by non-native speakers with mild or heavy accents. To reduce the role of simple prejudice about a speaker's knowledge, listeners were told that the speakers were reading statements written for them by the researchers. The speakers were not sharing their own beliefs.

What it found

In the first experiment, according to the University of Chicago's report of the study, statements read by native speakers received an average truth rating of 7.5. Statements read with a mild accent averaged 6.95, and with a heavy accent 6.84. The differences were small, but they appeared even though listeners knew the speakers were reading a script.

In a second experiment, listeners were told in advance that the study was about whether accents affect credibility. With that awareness, mildly accented statements were rated as true as native ones. Heavily accented statements were still rated lower.

The authors' explanation was not about prejudice. Accented speech can take a listener slightly more effort to process, and people tend to treat ease of processing as a sign of truth. Keysar put it this way: listeners "misattribute the difficulty of understanding the speech to the truthfulness of the statements."

Did it hold up?

This is where the story becomes less tidy.

Several studies found no effect. A 2024 paper by Lorenzoni, Faccio and Navarrete in the Journal of Cognition summarises the attempts before reporting its own experiment. Souza and Markman (2013) ran a direct replication with native speakers and speakers with Brazilian Portuguese and Korean accents and found no difference in credibility. Ladina Stocker (2017) tested 194 French-speaking and 183 Swiss-German-speaking listeners in Switzerland, rating 48 trivia statements in four accents. Listeners did hold different stereotypes about the credibility of different language groups, yet the accent did not change how true they rated the statements. Mathis Wetzel, Sandrine Zufferey and Pascal Gygax (2021) compared familiar and unfamiliar native and foreign accents in French and found that foreign-accented statements were not rated as less truthful; their statistics gave strong support for no effect.

Some studies found part of it. The same review describes other work, including Hanzlíková and Skarnitzl (2017), as partly confirming the original pattern.

A follow-up on exposure, and its replication. In 2021, Boduch-Grabka and Lev-Ari reported in Cognitive Science that British listeners rated statements in a British accent as more true than statements in a Polish accent, and that a short exposure to Polish-accented speech beforehand narrowed the gap, because listeners then understood the accent more easily. That is a hopeful result. But in 2024, a team at the University of Utah ran a preregistered close replication of that study, published in Studies in Second Language Acquisition. They found no effect of accent or of exposure on how true the statements were rated. They noted that their result does not rule out the processing explanation, but suggested the accent effect may not be robust.

A different test, the same answer. Lorenzoni and colleagues' own experiment used the "illusory truth" method, in which repeated statements usually feel truer. Repetition worked as expected, and it worked equally for native and foreign-accented speech. Foreign-accented speakers were rated lower on some social traits, but those ratings did not predict whether listeners believed what they said.

Our reading. The specific claim that a foreign accent makes trivia statements sound less true has not reliably replicated. The underlying ideas have better support: unfamiliar speech can take more effort to process, exposure makes it easier, and listeners can hold stereotypes about speakers. None of this is about the speaker.

How it gets misused

• "People do not trust you if you have an accent." This overstates a small, inconsistent effect from lab ratings of trivia statements.
• "So get rid of your accent." Nothing in this research suggests that. Where an effect appeared, the explanation pointed at the listener's processing and at familiarity, and exposure was the remedy studied.
• Ignoring it entirely. Mixed evidence is not proof of no bias. Listeners in Stocker's study held stereotypes, and Lorenzoni's listeners rated foreign-accented speakers lower on some traits. Bias in how people judge speakers is worth taking seriously, even if this particular truth effect is shaky.

What it means for you

At Brightside we never ask anyone to erase an accent. An accent carries where you are from and who you are. The aim is simpler: to be understood the first time, by the people you need to reach. That is a shared job between speaker and listener.

If you are the speaker, on a call with a buyer abroad, presenting to a regional office, or speaking at a town hall, three habits help any listener, whatever your accent:

• Pace. Slow down slightly on the sentences that matter most, and pause after them.
• Signposting. Tell people where you are going: "Three points. First..." It reduces the effort of listening.
• Stress the key words. Put clear weight on the number, the date, the decision.

"The total is forty-two thousand. Four, two. And the deadline is the fifth of March."

If you are the listener or the manager, the research gives you more to do:

• Notice effort, and do not mistake it for doubt. If you find a speaker harder to follow, that is information about your ear, not about their honesty or skill.
• Seek exposure. Familiarity makes unfamiliar speech easier to process, which is exactly what the exposure studies set out to test. Listen widely, on purpose.
• Ask, then judge. Before you decide a point was weak, check you heard it.

"I want to be sure I have this right. Could you take me through the second point once more?"

Sources

1. Shiri Lev Ari and Boaz Keysar, Why don't we believe non-native speakers? The influence of accent on credibility, Journal of Experimental Social Psychology 46(6), 1093-1096, 2010, record at Royal Holloway. pure.royalholloway.ac.uk/en/publications/why-dont-we-believe-non-native-speakers-the-influence-of-accent-o
2. University of Chicago News, Foreign accents make speakers seem less truthful to listeners, research shows, 19 July 2010. news.uchicago.edu/story/foreign-accents-make-speakers-seem-less-truthful-listeners-research-shows
3. A. Lorenzoni, R. Faccio and E. Navarrete, Does Foreign-Accented Speech Affect Credibility? Evidence from the Illusory-Truth Paradigm, Journal of Cognition 7(1), 26, 2024 (reviews Souza and Markman 2013, Hanzlíková and Skarnitzl 2017 and others). pmc.ncbi.nlm.nih.gov/articles/PMC10885845/
4. Ladina Stocker, The Impact of Foreign Accent on Credibility: An Analysis of Cognitive Statement Ratings in a Swiss Context, Journal of Psycholinguistic Research 46(3), 617-628, 2017. doi.org/10.1007/s10936-016-9455-x
5. Mathis Wetzel, Sandrine Zufferey and Pascal Gygax, Do non-native and unfamiliar accents sound less credible? An examination of the processing fluency hypothesis, Journal of Articles in Support of the Null Hypothesis 17(2), 61-70, 2021. www.jasnh.com/pdf/Vol17-No2-article3.pdf
6. K. Boduch-Grabka and S. Lev-Ari, Exposing Individuals to Foreign Accent Increases their Trust in What Nonnative Speakers Say, Cognitive Science 45(11), e13064, 2021. doi.org/10.1111/cogs.13064
7. Samantha Barlow and colleagues (corresponding author Rachel Hayes-Harb), The effects of exposure and explicit stereotypes on veracity judgments of Polish-accented English speech: A preregistered close replication and extension of Boduch-Grabka & Lev-Ari (2021), Studies in Second Language Acquisition 46(5), 1320-1336, 2024. www.cambridge.org/core/journals/studies-in-second-language-acquisition/article/effects-of-exposure-and-explicit-stereotypes-on-veracity-judgments-of-polishaccented-english-speech-a-preregistered-close-replication-and-extension-of-boduchgrabka-levari-2021/EF03B7A762B1442206B537F0AD4447A4

Published by The Full Stop, the journal of Brightside English, in the The Experiments series. Every factual claim links to a source below; where accounts or findings are disputed, we say so. Sources checked on 26 Oct 2026. Reviewed by a Brightside senior coach. Corrections: see our editorial standard.