The discrepancy between individuals’ intention to disclose data and their actual disclosure behaviour is called the privacy paradox. Although a wide range of research has investigated the privacy para-dox, it remains insufficiently understood due to mental processes’ role in decision-making being most-ly neglected. This research-in-progress provides a theoretical concept that examines the cognitive processes underlying data disclosure decisions to provide a better understanding of the privacy para-dox. We apply the Elaboration Likelihood Model (ELM), which suggests that the mental shortcuts that individuals take when making their actual data disclosure decision, which differs from their self-reported data disclosure intention, cause the privacy paradox. We propose a two-step, mixed method approach comprising a survey and an online experiment to empirically explore the intended and actu-al data disclosure. The study takes theoretical and methodological issues in prior literature into ac-count and enhances our understanding of individuals’ paradoxical data disclosure behaviour from a psychological point of view.