Public attitude surveys provide invaluable data for assessing perceptions, values, and attitudes across societies and over time. Ideally, respondents feel secure to disclose accurate information (avoiding reporting bias and item non-response) in the context of a face-to-face interview. Yet, survey research seldom accounts for peer effects caused by bystanders. The existing research focuses primarily on the effects of parents and spouses on self-reporting illicit activities or marriage-related issues. Using survey data from the Afrobarometer, this paper finds that bystanders, especially non-familial ones, substantially affect responses to an array of questions (some sensitive and some not), which are typically consistent with a socially desirable response. In parallel, both family and non-family bystanders also increase the rate of 'don't know' responses relative to private interviews. These findings provide further support for designing new approaches to secure private interviews and implementing alternative techniques in face-to-face survey methods to limit bias and capture 'true' opinions.