If the core of personal intelligence involves reasoning about personality itself, then what is personality? In a editorial for the newsletter of the Association for Research in Personality, I encouraged my colleagues to begin “Asserting the Definition of Personality,”  because so many people misunderstand what personality is. (The original article is here; you need to scroll down the page to find it).

I’ve argued there that there is a considerable consensus as to personality’s definition within the discipline of personality psychology itself:

personality is a system of parts that is organized, develops, and is expressed in a person’s actions (Mayer, 2007, p. 1).

The parts of personality are an individual’s major psychological systems. These include a person’s motives and emotions, thoughts and intelligences, social styles and skills, and awareness and self-control.

So personal intelligence concerns the ability to reason about the personality system–whether the specific personality is our own or belongs to another person. Our reasoning includes the ability to describe personality and to reason about what we should do based on our personality and about what other people will do based on their personalities.

The definition of personal intelligence I use also specifies that we reason about “personality-relevant information” in addition to personality. Personality-relevant information includes clues to personality and influences on personality. As personality functions, it interacts with its inner psychological systems—motives, emotions, intelligences, and the like—and also with its surrounding environment. All of those psychological systems within us and around us contain information relevant to personality. For example, if a person is sad, his perceptions of the surrounding world will be skewed somewhat to the negative. Sadness, in this case, is personality-relevant information. Similarly, we leave traces of ourselves in the environments that surround us—we talk to our friends, decorate our homes, choose what to wear. All of those acts and choices are potentially personality-relevant in that they reveal something of our personality.

Personal intelligence involves the capacity to reason about personality and personality-relevant information so as to better understand ourselves and our acts, and to better understand other people; at its heart lies the understanding of personality itself and the information that pertains to it.