The use of Purple Monkeyflower (Mimulus kelloggii and related species) to support or treat emotional sensitivity is primarily rooted in tradition, specifically within the context of flower essence therapy. Developed by Dr. Edward Bach in the 1930s, flower essences are diluted solutions of flower material believed by proponents to address various emotional and psychological states. Purple Monkeyflower is one of the remedies in the Bach flower system, intended to help individuals who are highly sensitive to emotional influences and environmental stimuli.

However, there is no robust scientific evidence to support the efficacy of Purple Monkeyflower or any flower essence in treating emotional sensitivity or related mental health conditions. Clinical studies on flower essences in general have failed to demonstrate effects beyond placebo. The theoretical framework for flower essences is not consistent with established scientific understanding of biology or psychology. Accordingly, the evidence supporting the use of Purple Monkeyflower for emotional sensitivity is rated as 1, reflecting its use in traditional or alternative healing systems but lacking empirical validation.

In summary, Purple Monkeyflower's use for emotional sensitivity is justified by tradition and anecdotal reports within the flower essence community, rather than by scientific research or clinical trials.