Interpersonal relationships, PNI, and health: Seeds in the 1980s, fruiting trees today.

In this contribution to the Special Issue, I highlight how Janice Kiecolt-Glaser's research in the 1980s planted the seeds for two areas of social relationships and health research: loneliness and intimate/marital relationships. I review the foundational "seed" studies from the mid-to late-1980s, the research "saplings" that sprouted and grew during the subsequent twenty years, and the "mature trees" that have gone on to fruit and grow their respective areas of inquiry over the past twenty years. In addition to highlighting the mature trees that have borne rich empirical fruit, my other goal for this contribution is to draw attention to ideas and concepts from Kiecolt-Glaser's work and writing that merit further conceptual and empirical examination in the next generation of research on social relationships, psychoneuroendocrinology, psychoneuroimmunology, and health.