The study features piloting of a randomized trial to determine whether an internet-based positive psychology (PP) intervention is associated with greater improvements in blood pressure compared to an attention control condition. The pilot trial additionally evaluates the efficacy of the internet-based PP intervention with respect to psychological well-being, hypertension-related health behaviors, autonomic cardiac control, and high-sensitivity C-reactive protein. Serum blood assays will facilitate exploration of mechanistic indicators linking psychological well-being to cardiac functioning.