Abstract
The benefits that an individual can derive from plants have been discussed for thousands of years, yet historically, reports supporting many of these benefits have been anecdotal. The problem with anecdotal evidence involves its veracity: we cannot know if the implied effect is due to plants or other factors. Anecdotes are valuable, however, because they can give researchers ideas about experiments to conduct. In the last twenty years, studies testing hypotheses about how plants affect individuals have begun to appear. This paper briefly reviews the methods and results from a selection of these studies.