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Personality and System Development:
What's the Connection?

by Elizabeth A. Buie (copyright notice)


Does this sound familiar?

Joe (excitedly): "Hey, Fred! I've just thought of a terrific improvement for the system!"
Fred: "If it ain't broke, don't fix it."
(Joe thinks: "He's stuck in a rut!")
(Fred thinks: "I wish he'd leave well enough alone.")

And this?

Mary: "Alice, do you think the new payroll system will be finished on time?"
Alice: "Relax, it isn't due for another six months."
(Mary thinks: "She's such a procrastinator.")
(Alice thinks: "She's too uptight about schedules.")

If your group is like most, these situations are typical. As system developers — SDers — we do share certain personality traits (see, for example, Michael L. Lyons, "The DP Psyche," Datamation, August 15, 1985; and Sherry Turkle, The Second Self: Computers and the Human Spirit, Simon and Schuster, 1984). But we also differ among ourselves. These differences can interfere with system development unless we understand them. Let's examine SDer personality in the framework of Jungian psychological type.

The dimensions of Jungian psychological type

The theory of psychological type was first described in the early 1920s by Swiss psychiatrist Carl Gustav Jung. During World War II, Isabel Briggs Myers and Katharine C. Briggs developed the first version of the Myers-Briggs Type Indicator® (MBTI®), to identify personality in four dimensions of psychological type:

These dimensions address habitual preferences, like whether you are right- or left-handed. Try this: Write your name as you normally do. Now do it with your other hand. Although you can write with your less preferred hand, you probably don't do it as well and it doesn't feel natural. The preferences identified by the MBTI operate the same way.

You have preferences in all four dimensions. The strength of each preference may be anywhere from very high to very low, but the direction determines your psychological type. If, for example, you prefer thinking to feeling — no matter how strongly — you are a "thinking type." In Myers-Briggs terminology, you're a "T."

The Myers-Briggs approach to personality is non-judgmental: no preference or type is inherently better than any other. Each type contributes to teamwork. Different types do tend to choose different occupations and work environments, but this doesn't guarantee that an individual will be suitable (or unsuitable) for work that is generally chosen (or avoided) by his or her type. Let's look at the types and their work styles, and then we'll examine the implications for system development.

The first dimension of psychological type represents your habitual orientation of energy. Extraversion and introversion are, respectively, outward and inward orientations.

The second dimension concerns your function of perception, your way of gathering information. Sensation takes in facts, details, and reality, while intuition pays attention to meanings, the big picture, and possibilities.

Think of it this way: N's see the forest while S's see the trees.

By whichever function you gather information, you use your function of judgment to organize it and make decisions about it. The third dimension of psychological type comprises thinking judgment, which is objective and logical, and feeling judgment, which is subjective and personal.

The fourth and final dimension of psychological type concerns your attitude toward structure: judgment or perception. Judgment involves order; perception, flexibility.

Distribution of types

The types are unevenly distributed in the population. Extraverts, for example, enjoy a 75% majority in the United States; so do sensing types. But T's and F's are half-and-half, and J's at 55% just barely outnumber P's. The thinking/feeling dimension alone shows gender differences: about 60% of men and 40% of women prefer thinking. (These distributions come from the MBTI Manual, 1975.)

Each dimension of type has its own brand of misunderstanding. E's can become frustrated by not knowing what I's are thinking; I's may see E's as shallow. S's tend to see N's as impractical and scattered; N's may see S's as plodding and unimaginative. F's may come across to T's as muddleheaded and emotional; T's may seem cold-hearted and unfeeling to F's. And J's and P's tend to see each other as compulsively scheduled or unscheduled.

 [Figure 1. Distribution of Types in the United States] The four independent dimensions, each with two complementary preferences, give rise to sixteen psychological types. Figure 1 presents a type table showing the estimated occurrence (in the U.S.) of each type and each preference. Notice that over half the population (56.4%) prefers extraversion and sensing (shaded border).

Now, you may be wondering how all this relates to system development. "Sure," you say, "this explains a lot about my group. But how can I use this stuff?"

As you've probably noticed, SDers are a special breed. We're somehow different from the masses. (Don't ask me whether this is good or bad. :-) But when we look at how we're distributed on the type table (Figure 2), we see that as a group we are more

than would be expected in a randomly chosen group of Americans. The first three differences are striking; all four are statistically significant (p < .0001, chi-square tests). What's more, over half of all SDers are ISTJs, INTJs, or INTPs (highlighted areas), while only about 8.2% of Americans belong to one of those three groups.

 [Figure 2. Distribution of Types among System Development Personnel 
         (from Lyons, 1985, n=1229)] This typological profile of system developers has two aspects: variation within the profession, and differences from the general population. The first affects our teamwork and the quality of our systems. The second affects our relationships with our users/customers and our ability to meet their needs. Let's look first at teamwork.


Most of what goes on during system development — analysis, design, coding, testing, debugging, technical documentation, etc. — is essentially solitary work involving logical analysis. No wonder we have so many introverts and thinking types! These two factors — the preponderance of I's and T's, and the importance of introverted and thinking behavior (even by E's and F's) — lessen the effect of E/I and T/F on teamwork among SDers. Still, these differences matter. If, for example, extraverts dominate a meeting, or if introverts hesitate too much before speaking, the potential contributions of the introverts can be lost. And if T's are too critical, or if F's take it too personally, possible solutions can be overlooked.

Nonetheless, S/N and J/P do have larger effects on teamwork among SDers. First, we're almost half S's and half N's. We have over twice the percentage of intuitives in the general population. And both sensation and intuition clearly contribute to system development, but their approaches are so different that these types often have trouble appreciating the other's value. Second, although we have J's and P's in the same proportion as I's and E's, our J/P ratio is much closer to that outside the profession. And both organization and flexibility have clear advantages.

Effect of S/N and J/P

Review for a moment the situations of conflict that opened this article. Joe is an intuitive type, always thinking up new possibilities and wanting to change things. Fred is a sensing type, trusting in established methods and not wanting to rock the boat. Each has his strengths and weaknesses. Both types are necessary for a balanced approach to system development, where we must evaluate both new and established methods without a priori placing greater trust in one or the other. But Joe and Fred are so caught up in their own perceptions that each fails to recognize the value of the other's way.

What can Joe and Fred do? Well, Joe can tone down his enthusiasm. He can say, "I've thought of a possible improvement for the system, and I'd like to explain it to you and see what you think. Maybe you can help me figure out whether it's practical." And Fred can put aside his distrust of change. He can offer to help Joe examine the practicalities of his ideas.

In the second situation, Mary is a judging type. She's concerned about organizing and scheduling. Alice is a perceiving type, more interested in flexibility and open options. Mary is focusing too far in the future; Alice is resisting any talk about schedules. Planning and scheduling certainly play an essential role in any system development project, but a team that is overly strict about schedules may find itself unable to accommodate changes in requirements or design. And I've yet to hear of a project where some changes didn't happen!

Mary and Alice can accommodate each other too. Mary can ask whether Alice is on schedule for the next month or two. If Mary gets too far ahead, Alice can tell her the status of more immediate objectives. Mary can help Alice with longer-term goals by assisting her in setting interim deadlines, which Alice finds easier to keep in mind. And Alice can help keep Mary from making too-quick decisions.

Effect of E/I and T/F

As S/N and J/P primarily affect our relationships with our colleagues, E/I and T/F mainly affect our relationships with the outside — customers and users. For example, E's find it easier than I's to communicate with people, and they usually don't mind interrupting what they're doing to talk to a customer.

Kathy Brittain White, of the University of North Carolina at Greensboro, has documented the contribution of feeling types to system development. (See, e.g., "MIS project teams: An investigation of cognitive style implications," MIS Quarterly, vol. 8, 1984, pp. 95-101.) In one study, White compared two management information systems (MIS) teams that were given the same assignment. One team included no feeling types. This all-T team failed to complete the project successfully: users complained that team members spoke in overly technical language and that the system produced did not meet their needs. The other MIS team contained 50% F's. In this case, according to White, the users "consistently expressed satisfaction, not only with the end products or systems produced, but also with the process used." They felt that this team was genuinely concerned about their needs.

Thus, the benefits of balance outweigh the difficulties of internal communication. As Myers put it, "If people are exactly the same type, they will understand each other very well but will not make the strongest team because they will be prone to commit the same mistakes."


Type and system development team building

Ergo Sum Workshops

I conduct MBTI workshops for system development teams that have worked together long enough to have developed patterns of interaction. These "ergo sum" workshops, as I call them, focus primarily on internal teamwork and pay some attention to relationships with customers. Participants complete the MBTI several days beforehand, so that I can determine the type distribution of the team before I decide how much emphasis to place on each dimension. I begin the workshop by explaining the preferences and giving participants a chance to guess at their types. Then I distribute the MBTI results and we discuss how well they fit. We spend the rest of the time in exercises.

In each exercise, the team splits along one dimension — e.g., into a sensing group and an intuitive group. The smaller groups discuss among themselves a number of questions pertinent to this dimension, and they record their answers on large sheets of paper. Then we return to the large group. The small groups' answers are taped to the walls, and we compare them — examine their strengths and weaknesses — and discuss their implications for the team's work.

At the end of each session (workshops usually involve half-day sessions), we evaluate. We discuss what team members have learned, what more they might need, and how they can use what they've learned.

A manager of one system development operation sees definite improvements in one of his teams after an MBTI workshop. "They're more sensitive in general," he says. "They appreciate each other's differences, and they recognize that a good mix of people is important. Before [the workshop], they wanted everyone to be like them," but now, he notes, they'll suggest bringing in someone of a type the group needs. He often overhears his people mentioning type during "hallway conversations," and he points to several specific improvements in their teamwork:

Using type in your organization

Even without an MBTI workshop, you can still put knowledge of psychological type to use in your group:

  1. Familiarize yourself with the types and their work styles. Read the MBTI Manual or Gifts Differing (both available from Consulting Psychologists Press).
  2. Determine, as well as you can, your own type. Seek a qualified professional to administer the MBTI to you (the Association for Psychological Type (APT) is a good source of information on MBTI professionals in your area). If this isn't feasible, try the Keirsey Temperament Sorter (D. Keirsey and M. Bates, Please Understand Me, Promethius Nemesis Press, 1978).
  3. Notice your own patterns of interaction with your coworkers, family, and friends. Pay special attention to people who drive you nuts and people with whom you really click. Try to figure out the role of type in these relationships.
  4. Do some "type-watching." Observe other people's patterns and make guesses about their types. Interact with your coworkers according to your guesses, and see what happens. Make new guesses as necessary.
  5. Discuss type with your group. Invite their comments and speculations. Be open about your own type and your patterns.

We can't expect guarantees when dealing with people. And psychological type certainly doesn't explain everything about personality. But it does provide an effective framework for understanding and working with some very basic human differences.

And that can make all the difference.


In Latin, the phrase ergo sum means "therefore I am", and reflects the self discovery that an individual can experience. Using the Greek meaning of "ergo" ("work") and the English meaning of "sum," the phrase reflects the synergy that can occur when teams understand and respect their differences, and use them constructively.

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This article was published in the January 1988 issue of System Development. Copyright © 1988, 1997, Elizabeth A. Buie. (A condensed, unauthorized version was also published in the May 1988 issue of CMA Magazine, under the byline of Harvey Gellman. Mr. Gellman has acknowledged that it is my work and has paid me the fee he received.) All rights reserved. Permission is granted to print this page or link to it, as long as such use is personal or educational and is not for commercial gain or profit. This article may not be republished or redistributed without permission.
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Last updated 29 April 2006, to revise the visual design