The short version as found at:
http://www.namastecafe.com/evolution/indigo/
"The Indigo Child is a boy or girl who displays a new and unusual set of psychological attributes, revealing a pattern of behavior generally undocumented before. This pattern has singularly unique factors that call for parents and teachers to change their treatment and upbringing of these kids to assist them in achieving balance and harmony in their lives, and to help them avoid frustration." -- Lee Carroll & Jan Tober