As part of an investigation into how people use language to persuade other people to agree with them, Dr Briony Pulford examined how confident people feel in the advice that they’re giving when they can also see the advice and level of confidence of another advice giver.

Eighty participants gave written advice to a friend about the truth/falsity of 16 general knowledge statements. A high or low financial reward was supposedly at stake for the friend who received the advice. Participants saw the statement of general knowledge and also the advice that another person was also giving to the friend.

The status of the other person (high/ low) was crossed with their gender (male/female advisor), and their level of certainty in their advice (high/low confidence). This resulted in eight statements, such as 'This is definitely true: Professor Jane Harte'. The written advice that participants then gave was scored by two raters for the level of confidence/certainty it conveyed.

Dr Pulford found that, with low rewards, advisor confidence significantly influenced how confident participants felt when the advisor had high status, but it was unimportant when the advisor was of low status. A high-confidence, high-status speaker inspired participants to express higher confidence in their own advice in the low reward condition.

Gender also exerted a noticeable influence. Participants had the highest certainty in their own advice after hearing advice from highly confident female advisors.