What is the Biblical definition of personality?

Here it is, sweet and short, I cannot find one, and that is not because I have not been looking and asking around -- for years, as a matter of fact. It was a question I had back in the 60's while working on my BS in psychology. I have heard Christians use the term as though they knew something about which they were talking, but whenever I would press them to the wall for a definition, their arguments turned to Jell-O, and I think for good reason.

Personality is a term we use to label a "construct," or collection of “constructs.” Put a bit too simply, a construct is a hypothetical concept, model, or schema which researchers create and use as a tool to describe some "thing" they cannot directly observe in nature or human behavior. Self esteem, motivation, and intelligence (IQ), are examples of constructs, as is gravity. Yup, gravity. We use this construct to explain why objects are attracted to each other. Why, for example, objects are attracted to the center of the earth – fall downwards. But we cannot see gravity, just its effects, which we can predict with amazing accuracy.

When we use the term "personality," we are referring to some package of traits we observe that makes one person different from another, which we use to organize people into groupings. We use the term personality so casually that it appears that we all know what it is, but give ten people paper and pencil to write down just what personality is and you will end up with ten rather useless descriptions.  We all know what it is, but just cannot define it. Well, psychologists and researchers are in the same boat, so they resort to creating a construct in order to study it and make some sense of it. And, strange as it might sound, this approach works! Here's how.

Let's say you are a researcher seeking to understand what makes people tick – personality –  who has observed the different ways people relate to groups. Some seem to seek out and be energized by groups, others seem to avoid and quickly tire in them. You cannot put your finger on it, but you know there is something there to study. So, you create labels, say "introversion" and "extraversion." Now, these are your created constructs, so you get to define them anyway that makes sense to you, and then formulate a way to measure them. You interview folks, asking lots of questions which you refine with experience to the point that you can now ask these questions to any individual and determine by his or her answers how that person will likely react in a group environment. And wouldn't you know, it works. You are able to predict with amazing accuracy how these folks will behave.

You could publish your work, claiming that you have discovered two "personality traits," introversion and extraversion.  As you are about to go to press, someone gently pulls you aside and points out that your two “personality traits” do not match all that well with two older Greek personality traits, sanguine and phlegmatic. So who is right? Well, you both are. How can this be? Remember that “personality” is a construct based on a theory and, if you have two theories of what constitutes “personality,” both will have its own construct(s) within that theory of what makes up personality, so they do not conflict. It is like two cities having different laws for overnight parking. They might sound contradictory, but each is true within its own city limits. Sound useless or confusing? Not really, once you stop insisting that there is one, and only one, label that qualifies as a person’s “personality.” Nevertheless, there is a practical benefit despite the inability to nail this “personality” thing down to our satisfaction.

The theorists who described personality back in Greek times, had a theory that  behavior was controlled by four body fluids, each producing a distinct behavior pattern. Sanguine, influenced by blood, and phlegmatic, influenced by phlegm, are descriptions of two sets of quite different constructs. This theory of personality might be useful to you if, let us say, you are making up a list of guests for a party and you want to ensure that it will be a lively, noisy, fun loving party by including only sanguine “personalities” rather than any phlegmatic ones. Today, those theorists who believe personality is a grouping by "personal preferences" (e.g. Meyers-Briggs followers), are comfortable using constructs like introversion and extraversion. Using this more modern theory of personality would not cut it for your party list as there are some very fun loving (sanguine) introverts, and some very stolid (phlegmatic) extraverts. You could have a nightmare of a party if you thought extraverts would be the ticket to your party goal, and introverts would be counterproductive. But, if you were entertaining a new client for a big contract, you might really profit by knowing whether he or she prefers introversion or extraversion. Invite an introvert to a large gala of your employees and you might find that he or she is in no mood to talk business and wants to huddle with just one or two or leave the party early. Invite an extravert to a one-on-one meeting and you might find him or her tiring easily. (I am exaggerating outcomes here just a bit to make a point.)

So, “personality” is often a set of constructs which reflects the theorists' focus of concern. There are many "personality" tests on the market, and each yields valid information within the particular theory upon which it is based. To determine which test to use, first know what questions the theory attempts to answer – what traits the theory holds to be crucial to defining personality. If they are the same as yours, then it might be the right test for you to use – the right theory for you. Just be careful that you do not fall in the trap of mixing constructs from different theories. Be consistent within the theory of your choice lest you find yourself believing the equivalent of having to abide by another city’s parking laws and create more confusion and contradictions. It is not uncommon to hear ignorant folks mix Myers-Briggs, D.I.S.C., Taylor Johnson, or other test results by mixing the constructs on which they are based. They might sound like they know what they are talking about, but they cannot stand examination or application. If we had this thing all figured out, there would only be one theory. Mixing theories only adds to the confusion.