Our brain's internal processing is limited. Therefore, the five-paragraph essay, the structure of the essay: one introductory chunk that introduces a thesis, three supporting notions that back up the thesis, then a reiteration and, perhaps, a slight extension of the thesis, is customized for our brain to retain information. The five-paragraph is build to work with our working memory.

In 1956, Harvard cognitive psychologist George Miller published, “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information. ”