Receiving high-quality, responsive support in times of distress is critical but difficult. In a theoretical review, we previously proposed a process model that explains why support-seekers’ positive expressivity can elicit—but may sometimes suppress—supportive responses from partners (providers) within distress-related contexts. In the current work, we aimed to test direct and indirect pathways linking seeker’s positive expressivity in negative disclosures to provider’s support while addressing notable gaps in the existing literature. Studies considered seeker-expressed positivity as broad, unitary construct (Studies 1, 2, and 4) and explored different types of positivity (Studies 1, 3, and 4): partner-oriented positivity (e.g., gratitude), stressor-oriented positivity (e.g., optimism), and unspecified positivity (e.g., pleasant demeanor). In behavioral observation studies of romantic couples (Studies 1 and 4), seeker-expressed positivity in negative disclosures positively predicted provider responsiveness, even when controlling for seeker-expressed negativity and other plausible third variables. Online experiments with manipulations of seeker-expressed positivity (Studies 2 and 3) yielded causal evidence of positivity’s direct support-eliciting effects. Considering positivity types, partner-oriented positivity and stressor-oriented positivity showed the most robust support-eliciting potential; unspecified positivity also appeared valuable in some contexts. Evidence for several of the model’s indirect pathways emerged in correlational (Study 4) and experimental (Studies 2 and 3) work, providing insights into support-eliciting and support-suppressing mechanisms through which positivity operates. These findings underscore support-seekers’ active role in obtaining support, highlight the value of positive expressivity for eliciting high-quality support, and lay the groundwork for further research on positive expressivity’s effects in support-seeking contexts.