The communication and influence of confidence and uncertainty
This thesis reports a series of nine inter-linked experiments examining the influence of different levels of verbal confidence on choice and interpersonal perceptions. Chapter 1 identifies the levels of confidence associated with some everyday expressions of confidence, expressions that are used as ‘confidence cues’ in subsequent experimental chapters. Chapter 2 examines the influence of confidence cues with different types of task, and Chapter 3 relates these influences to individual differences. Chapter 4 considers our perceptions of speakers who express different levels of confidence, then Chapters 5 and 6 examine whether these perceptions, and the subsequent use of their information, change when performance feedback is made available. Chapter 7 examines whether our own confidence level affects the extent to which a speaker’s confidence influences us then Chapter 8 determines if a speaker’s confidence exerts a positive or negative influence, while Chapter 9 investigates how the influence of confidence is influenced by the timing of the advice. The results indicate that confidence is an effective form of influence, providing evidence that a confidence heuristic is used, whereby a speaker’s confidence is taken as a cue to their accuracy, knowledge, and competency. The extent to which the confidence heuristic is used when making choices strongly depends on one’s own level of confidence, whether this was due to the type of task being tackled, the difficulty of the task, or the timing of the advice, with people relying more on the confidence heuristic as their own confidence decreased, although there were some individual differences mediating the extent of this. Increasing levels of speaker confidence lead to speakers being perceived more positively in terms of competency, but too much confidence was found to be detrimental in terms of how much a speaker was liked. Issues raised by this thesis, and directions for further research are considered in the Discussion.