ACT and CBT Bibliotherapy for Perfectionism

The goal of this clinical trial is to test self-help books for adults with perfectionism. The main questions it aims to answer are: 1. Are the self-help books (ACT and CBT) effective, compared to a waitlist control condition? 2. What are the processes of change for perfectionism in ACT vs. CBT bibliotherapy? 3. Do the self-help books (ACT and CBT) affect change in general distress, well-being, and affect? 4. Is bibliotherapy an acceptable and feasible intervention for perfectionism? Participants will be randomized into either the ACT self-help condition, CBT self-help condition, or waitlist control condition: 1. Participants in both intervention conditions will be asked to read the respective self-help book over the course of 10 weeks and complete 4 surveys over 3.5 months. 2. Participants in the waitlist condition will be asked to complete 4 surveys over 3.5 months, and will receive access to both self-help books once the study is complete.