Understanding Personal Construct Theory and George Kelly

Man is a Scientist!

The purpose here is to give you enough understanding of the background to Grid that you get the most out of what it offers, and that you don’t unknowingly do violence to the technique. It does not pretend to be a thorough exposition of Personal Construct Theory or to help develop interview skills, but to give you enough background to be able to plan, understand, and analyse a Grid interview


George Kelly

George Kelly began his career as an engineer, before becoming a clinical psychologist – which may explain his concern for precision. His work dates back to the 1930’s, but he was not a great self-publicist and his theories never really had a ‘champion’ such as you observe with some of his contemporaries. Repertory Grid, and Personal Construct Theory, have only rarely figured as ‘required reading’ for a qualification in psychology.

Kelly’s theory of personality is predicated on one axiom: that, as he put it, Man is a Scientist. In other words, from the dawn of consciousness each of us tries to make sense of the world as we experience it, and we do this by constantly forming and testing hypotheses about the world. By the time we are adults, we will have developed a very complex model of the world and our place in it: this model is, according to Kelly, our personality. Kelly’s theory of personal constructs develops this principle further – for example, by considering whether and how we modify our constructs when faced with contradictory information, what are our ‘core constructs’ – that is, the deeply-held values and principles which are unlikely to change, etc.

What is a Construct?

The term construct is particularly well-chosen, because it reflects the concept’s dual role. On the one hand, your constructs represent the view you have constructed about the world as you experienced it. On the other hand, your constructs indicate how you are likely to construe the world as you continue to experience it. Your construct system is your history and your predisposition to perceive.

As a simple illustration, let me relate a conversation I recently had with a friend who has the happy choice of at least four countries in which to spend her retirement. Talking about the criteria which would influence her choice, she said that one important criterion was the standard of care for the elderly and infirm. This was one of her constructs, and a very important one. It came as a complete surprise to me, because it had never been part of my construct system. When we talked about it, she said that several of her friends and relations had had long terminal illnesses and very different standards of care; and for the first time I realised that all the deaths I had known had been quick, and no-one had lingered in care. She had formed her construct on the basis of her experience, and that construct is one which she uses when thinking about countries to retire to. I didn’t have that construct, because my experience was different from hers; and so I would not have used it when thinking about countries to retire to – at least, not until the conversation gave me the opportunity to modify my construct system.

Kelly's Methodological Concerns

Kelly developed the Repertory Grid interview as a means of getting people to show him their construct systems. He had some very important methodological concerns about the standard of interviewing, especially in clinical psychology. His major concerns were:

  • Interviewer Bias. He had seen that the interviewer often contributes more to the diagnosis than the interviewee (remember that he was a clinician and these were the days when Freudians and Jungians and Behaviourists were quarrelling vigorously). I used to work for a major consultancy firm where the client’s problem depended very much on who answered the phone – though they weren’t allowed to have no problems at all.
  • Specificity in measuring, and where possible predicting, the characteristics of individual people and small groups. Psychology was a relatively new discipline, and many psychologists were seeking ‘laws’ of human behaviour. So there was the ‘rats, cats, and stats’ approach to studying behaviour, and large-scale studies showing the correlations between different aspects of personality and behaviour; but this was no good to Kelly, or to any other clinician, because they see people one at a time or in small groups.
  • Over-dependence on the expert. Clinical psychology at the time could be satirised as the patient lying on the couch while the ‘expert’ told him what was wrong with him. Kelly took the view that most people can take responsibility for understanding and, where necessary, adapting their behaviour; and that the role of the therapist would be more useful as a ‘skilled mirror.’

The Essence of Grid Technique

In order to circumvent these obstacles in his quest for the client’s construct system, Kelly invented the Repertory Grid interviewing technique. The essence of Grid technique is very simple:

  • Select a set of elements. The elements are concrete examples of the domain you wish to explore – for example, working with a client who had problems in making satisfactory relationships, the elements would be people with whom the client had relationships.
  • Take the elements in groups of three, and ask the question: ‘Can you tell me a way in which any two of these people are different from the third, in terms of ......?’ (The ‘in terms of’ phrase, called a qualifier, directs the client to consider the elements in a way appropriate to the purpose. So in this case the qualifiers might be ‘... in terms of how you feel about them, .... in terms of how they felt about you, .... in terms of how you behaved to each other,’ etc.) This two-against-one question produces a bipolar scale – for example had a sense of humour - I never saw him smile. This scale is a construct – note that it comes entirely from the interviewee. The interviewer has set up the parameters for the conversation, but has suggested none of the content.

There are ways of exploring the constructs in more depth and detail, but at some point in a full Grid interview the constructs are turned into scales (usually 1 to 5) and the interviewee rates every element on every construct. This gives you a matrix which can be analysed statistically in order to progress the discussion with the client. The statistical analysis answers Kelly’s need to measure people individually, and you could, for example, compare the person’s before-and-after perceptions. There are several analysis programs available, but it should also be stressed that it is not always necessary to use them. There are dangers, which will be explored later, in letting yourself become dependent on a computer program to do the work for you.

That is the essence of Grid. It is a powerful and content-free procedure. The interviewer sets up the session in order to meet the purpose, but provides none of the content. There is simply no other interviewing technique which will allow you to cover the breadth and depth of the interviewee’s map of their world. Its complete freedom from interviewer bias, and the transparency of the process, means that the interviewer can say to the client ‘All I’m doing is playing your own perceptions back to you.’ There have been times in my life as a consultant where I have had to present the results of a Grid-based research programme to the senior management, and I’ve known that they wouldn’t like it: being able to say ‘Fire me if you like, but they’ll still continue to think like that’ has been the only way I could get them to absorb the information.

Another useful feature of Grid is that because it is a standardised protocol, if you are conducting a large-scale research project with a number of interviewers, any interviewer can pick up the work of any other and understand what happened in the interview. You don’t have to have one of those awful reconciliation meetings where everyone has taken notes in their own way and you spend the first day explaining to one another.

Keeping Grid Free From Interviewer Bias

What does all this mean for a new Grid interviewer? At its simplest, it means that we have the means of knowing when, as interviewers, we have influenced the discussion. And because Grid can be completely free from interviewer bias, I suggest that we should keep it that way until and unless the purpose requires us to intervene. Some practical examples:

  • Don’t supply the contrast pole yourself. If the interviewee says ‘These two had a sense of humour,’ we don’t say ‘And the other one didn’t?’ We say ‘How would you describe the other, by contrast?’
  • Don’t summarise the interviewee’s constructs, either verbally or when you’re writing them down. If the interviewee says ‘She could almost always find two or three new ways of looking at a problem,’ that’s what you write. You don’t write ‘Creative problem-solver.’ And try to avoid asking the interviewee to summarise a construct, even if there are lots of words, because s/he may say ‘Creative problem-solver.’ What you have in the first phrase is a detailed, behavioural description of the element – and you’ll probably get a similarly specific description of the contrast pole – and later on you could find yourself needing that specificity.
  • Don’t imply that you’re judging the interviewee’s constructs, or waiting for a particular type of construct to appear. Yes, you do want to elicit constructs that are relevant to your purpose – that’s what the qualifiers are for – but in the early stages of a Grid interview you should respect the fact that the two-against-one process is not how most people are used to thinking and your first goal is to get them comfortable with it. Once they are comfortable with it, you can remind them of the qualifiers (for example ‘Could you look at these three in terms of ......’), or you can ask ‘Does that construct relate to the purpose?’ I once did a series of Grid interviews with managers and part-way through one of them said that he recognised the process because another consultant had used it on him a few weeks ago. I was playing it strictly by the book – I was a pair of eyes and ears and a pencil – and he said ‘You haven’t asked me to say anything about decision-making yet.’ I said that was up to him, whereupon he said that the previous consultant had said ‘Most managers have said something about decision-making by now,’ which he’d taken as a criticism. That’s the kind of thing I mean when I suggest that you shouldn’t imply that you’re judging the constructs.
  • A related point - it’s not for you to judge the importance of someone’s constructs. For example, a researcher interviewed a number of people and wrote ‘We stopped the interviews after eliciting twelve meaningful constructs.’ My question – who decided that they were meaningful? You, or the interviewee? And what exactly do you mean by ‘meaningful?’ It’s not your job to decide that. Much better is to elicit the constructs until the interviewee runs out; do a spot of laddering to change the focus and then ask if that has prompted any more constructs, and then ask the interviewee to sort the constructs into high, medium, and low priority.

Don’t Construe Other People’s Construing

One core value for a good Grid interviewer is: don’t construe other people’s construing. Don’t judge. Ask open questions – for example, if you can see a pattern in someone’s constructs (let’s say that there are a great many constructs about ‘sense of humour’ in the interviewee’s construing of key relationships) it’s better to ask ‘Can you see any patterns, or groups, in what you’ve said so far?’ than to say ‘You’ve got a lot of constructs about humour.’

Let’s be clear. I’m not saying that the interviewer should be completely passive. There will be occasions in any interview when questions or input from the interviewer are appropriate. What I am saying is: make as much use as you can of the unique opportunity Grid gives you to understand the interviewee’s world in their own terms before you interpose yourself in the process. Once you have interposed yourself, you’ll never get that state again. In the rest of this series, you’ll see that I advocate ‘letting the works show’ – that is, making the interview a joint endeavour, being open about the process and what you’re recording. Most interviewees will quickly find the process interesting and many become almost self-managing, and the interview becomes a co-operative process in which you offer techniques and they offer answers and insights.

Prepared by Dr Valerie Stewart

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