九型人格学（Enneagram）是一个有2000多年历史的古老学问，最早起源于古老的苏菲教派是游牧民族千年来经验的积累，和易经一样有千年历史。它按照人们习惯性的思维模式，情绪反应和行为习惯等性格特质，将人分为九种。

Enneagram一词源自希腊文ennea（九）以及gram（型态），可以译为九柱人格、九型人格或九种性格。原来的「九型人格」是一套灵修学问，以口耳传播，教派中的大师借此辨析弟子的性格类型，并依此指引他们灵修上的出路，帮助他们提升人格。

其后，九型人格学说辗转流传到欧美等地，美国心理学家海伦·帕玛（Helen Palmer）早年将它用作研究人类行为及心理的专业课题，更被包括史丹福大学在内的多所美国大学列作教材，成为心理研究课程。 而近代的九型人格于二十世纪六十年代兴起，由智利的心理学家 Oscar Ichazo 所创立。后来九型人格传入美国，加入了心理学元素，经不同学者集成并将之发扬光大。

The Enneagram of Personality, or simply the Enneagram (from the Greek words ἐννέα [ennea, meaning "nine"] and γράμμα [gramma, meaning something "written" or "drawn"]), is a model of human personality which is principally understood and taught as a typology of nine interconnected personality types. Although the origins and history of many of the ideas and theories associated with the Enneagram of Personality are a matter of dispute, contemporary Enneagram understandings are principally derived from the teachings of Oscar Ichazo and Claudio Naranjo. Naranjo's theories were partly influenced by some earlier teachings of G. I. Gurdjieff. As a typology the Enneagram defines nine personality types (sometimes referred to as "enneatypes"), which are represented by the points of a geometric figure called an enneagram, which, it is believed, also indicate some of the connections between the types. There are different schools of thought among Enneagram teachers, therefore their ideas on some theoretical aspects are not always in agreement.