Performing a dramatic act of religious devotion, creating an art exhibit, or releasing a new product are all examples of public acts that signal quality and contribute to building a reputation. Signalling theory predicts that these public displays can reliably reveal quality. However, data from ethnographic work in South India suggests that more prominent individuals gain more from reputation-building religious acts than more marginalized individuals. To understand this phenomenon, we extend signalling theory to include variation in people's social prominence or social capital, first with an analytical model and then with an agent-based model. We consider two ways in which social prominence/capital may alter signalling: (i) it impacts observers' priors, and (ii) it alters the signallers' pay-offs. These two mechanisms can result in both a 'reputational shield,' where low quality individuals are able to 'pass' as high quality thanks to their greater social prominence/capital, and a 'reputational poverty trap,' where high quality individuals are unable to improve their standing owing to a lack of social prominence/capital. These findings bridge the signalling theory tradition prominent in behavioural ecology, anthropology and economics with the work on status hierarchies in sociology, and shed light on the complex ways in which individuals make inferences about others. This article is part of the theme issue 'The language of cooperation: reputation and honest signalling'.
Keywords: Matthew effect; costly signalling; poverty trap; reputation; social capital.