This is all bullchit pseudoscience with no more real life application than sorting people by their horoscope sign
It's not, you obviously have not taken a closer look - I guess because the site in the OP looks girly and shallow.
The 16 temperament types were analyzed by Carl Jung and then by Myers-Briggs (http://en.wikipedia.org/wiki/Myers-Briggs_Type_Indicator)
The best thing to read on the topic is this book though: [ame="http://www.amazon.com/Please-Understand-Me-Character-Temperament/dp/0960695400"]Please Understand Me: Character and Temperament Types: David Keirsey, Marilyn Bates: 9780960695409: Amazon.com: Books[/ame]
It's an amazing book and a must-read if you wish to understand different motivations behind people's behavior. One of the authors is a real scientist btw

It's not some feel-good new age stuff or future-telling, it's just a typology of human personalities, and one that is very detailed and precise. Real life application is immense and reading this book if you have/plan a family or a relationship is very helpful.http://www.wickedfire.com//www.pinterest.com/pin/create/extension/