UC Santa Barbara

By taking a mixed-methods approach, this dissertation presents results from three studies that offer both qualitative and quantitative insights into how cognitive heuristics influence users’ risk perceptions and decisions about disclosure and privacy in the context of social network sites (SNSs). Findings from focus group interviews in Study 1 include numerous personal anecdotes about the effects of nine cognitive heuristics, which serve as proof-of-concept that illustrates how SNS users perceive these heuristics in relation to their disclosure and privacy decisions on SNSs. To complement the findings from the first study, Study 2A used a survey and “direct” measurement approach to examine the heuristics’ effects on privacy and disclosure via SNS users’ self-reported agreement with the effect of cognitive heuristics on their own decision-making processes. The findings from Study 2A help quantify and generalize the findings from Study 1 to a larger and more representative sample of SNS users. Due to the invisible and elusive nature of heuristic processes that largely occur subconsciously, Study 2B employs another survey-based study, but one that uses an “indirect” approach to measure the heuristics’ effects on four different SNSs (Facebook, Instagram, Snapchat, and Twitter) to examine potential correlational relationships between the cognitive heuristics and SNS users’ decisions about disclosure and privacy and to help improve the understanding of heuristic effects and their implications for SNS users’ privacy. The findings from Study 2B show that relying on cognitive heuristics (e.g., homophily heuristic, hyperbolic discounting, ephemerality heuristic, etc.) can result in negative consequences for SNS users’ privacy and that the underlying mechanism for these heuristic processes cannot be easily explained in terms of fully rational cost-benefit decision models, which so far have been popular in the literature (e.g., the privacy calculus model). The findings across the three studies in this dissertation not only help gain a deeper and more nuanced understanding of heuristic effects in the context of managing privacy on SNSs, but also demonstrate the importance of expanding scholars’ assumptions about human rationality when investigating privacy-related decision-making processes on SNSs. Overall, this dissertation provides results that contribute to the growing discussion about people’s bounded rationality and their reliance on cognitive heuristics when making decisions about privacy in the context of SNSs and offer future directions for research that could help SNS users make more informed decisions.