["Scandinavian Journal of Psychology, EarlyView. ", "\nABSTRACT\nAn overwhelming majority of the human population end up parenting a child, and the concept of family is arguably one of the most shared across societies. Thus, most people will at some point engage in thought processes about the prospect of becoming a parent, a prospect coupled with uncertainties (e.g., “Should I? Do I want to? Can I?”). The psychological processes underlying how individuals think about this decision—and what dispositional factors shape this deliberation—remain poorly understood. We addressed this gap by measuring thought engagement (how much individuals report thinking about parenthood and related factors) in a sample of 192 Swedish adults (58 parents, 134 non‐parents), and systematically comparing the predictive value of demographic variables, personality traits (e.g., extraversion), and dispositions toward risk and uncertainty using Bayesian multimodel inference. Intolerance of uncertainty (IU) emerged as a robust predictor of general thought engagement. Moreover, an interaction between age and occupation revealed divergent patterns: students showed increasing thought engagement with age, whereas employed individuals showed decreasing engagement. For domain‐specific thought engagement (e.g., economic concerns, parenting ability), demographic factors predominated, though personality traits also contributed, suggesting that dispositions shape what people think about rather than how much they think overall. These findings carry clinical implications: IU is a transdiagnostic vulnerability factor for anxiety disorders, and the inherently uncertain nature of the parenthood decision may be particularly distressing for some individuals. Our study provides empirical groundwork for future theoretical developments focusing on the psychological dimensions of fertility‐related decision‐making.\n"]