The table below offers some of the principal characteristics of the nine types along with their basic relationships. This table expands upon Oscar Ichazo's ego fixations, holy ideas, passions, and virtues[12] primarily using material from Understanding the Enneagram: The Practical Guide to Personality Types (revised edition) by Don Richard Riso and Russ Hudson.[13] Other theorists may disagree on some aspects. The types are normally referred to by their numbers, but sometimes their "characteristic roles" (which refers to distinctive archetypal characteristics) are used instead.[14] Various labels for each type are commonly used by different authors and teachers. The "stress" and "security" points (sometimes referred to as the "disintegration" and "integration" points) are the types, connected by the lines of the enneagram figure, that are believed by some to influence a person in more adverse or relaxed circumstances. According to this theory, someone classed as a One type, for example, may begin to think, feel and act more like a Four type when stressed, or more like a Seven type when relaxed.