Mind & EverydayFact
The famous seven items in your head are more like four.
George Miller named the "magical number seven plus or minus two" in 1956 as working memory's capacity. Nelson Cowan revised it in 2001 to about four chunks in young adults once tricks like inner rehearsal are ruled out. Children and older adults hold fewer.
Useful: Design instructions, menus and talks in groups of four, not lists of seven.
Source: en.wikipedia.org