Slow lies: sincerity is in the timing

Study co-author Dr Adam Wang from James Cook University said people form impressions of others based on how many seconds it takes them to respond to a question.

“Longer response times are often attributed to the person suppressing a raw, truthful response and fabricating a false one,” he said.

“Imagine asking a friend for their thoughts on a dish you cooked and being met with immediate praise for your culinary skills. Now imagine the same scenario with one difference: the response was delivered with a slight delay.”

However, there are exceptions.

“Our results suggest that the effect of response delay on perceived insincerity would be much weaker if the response is socially undesirable,” Dr Wang said.

“For instance, if someone asked you at a job interview whether you have had any experience in a similar job and you said ‘no’, regardless of how long it takes you to respond, they’ll likely see it as a sincere response.”

Dr Wang said being able to detect sincerity in others is important for human collaboration and trust, and can have significant implications in some high-stakes situations.

“For example, it has consequences when it comes to judging whether someone is guilty of a crime,” he said. “It is important that jury members or police exercise caution when using response time as a cue to determine culpability. Participants believed that slow denials are almost as much an indication of guilt as outright admissions of guilt.”

These findings are also relevant for politicians and other public figures.

“People often list sincerity as an important trait for politicians,” Dr Wang said. “But a politician taking care to answer a question thoughtfully could unintentionally give an impression of insincerity.

“These examples are why it’s important we’re aware of this unconscious judgement process because it would be unfair to misattribute response time to insincerity.”

Dr Wang said our reliance on response time is so strong, even when people were told to ignore it, they were still influenced by it.

“Most participants were more or less unwilling to completely ignore this piece of information,” he said. “Presumably because people believe intuitively that response time is an integral part of sincerity displays.”

The study involved experiments with more than 7500 participants from the US, UK and France who were asked to judge the sincerity of responders in different question-and-answer scenarios (presented as audio/video snippets or vignettes) with varying response delays.