It’s not my intention to give full information or an extensive discussion on every theory. This website is intended to be a starting point and the main difference with other websites is the visual representation of the theory, which I hope will help get to grips with the theory. There are also links it the bottom to get your further research started.

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Differentialism – Environmental Theory – Trait and Factor Theory

Frank Parsons


“In the wise choice of a vocation there are three broad factors: (1) a clear understanding of yourself, your aptitudes, abilities, interests, ambitions, resources, limitations, and knowledge of their causes; (2) a knowledge of the requirements, conditions of success, advantages and disadvantages, compensation, opportunities, and prospects in different lines of work; (3) true reasoning on the relations
of these two groups of facts” (Parsons, 1909, p. 5).

Although Parson’s book ‘Choosing a Vocation’ which was published posthumously in 1909, was a revelation at the time, reading it now will at least raise some eyebrows. Especially pages 66 and 67 with the header ‘Industries Open to Women’ will make you realise how far we’ve come. Having said that, Parson’s theory is still the most influential theory in career guidance and his ideas can be found in most career interventions. In short, Parsons proposes self investigation, investigation of the job market and matching the two for finding the career path that fits best with you or the client. Looking back, it’s not rocket science!

Environmental career theory or Matching by Frank Parsons.

The illustration above is just a representation of course. There are more than four categories. In fact every ‘job’ has its desired matching personality profile.


Parsons in context

The context of his theory sits firmly in the world of work of the day, where Fordism and Taylorism held sway. Everything was measurable and measured to improve efficiency in the midst of a world which was still heavily class based. The First World War hadn’t happened yet and domestic service, as well as social stratification in the job market from generation to generation, were still in full swing. On the back of this, career planning, in so far it happened in some classes in society, could be perceived in the same way: measured, rational and highly structured.


Parsons in practice:

His method for career counselling involves 7 steps (Parsons 1909, p.45):

  1. Personal Data: a statement of fact about the client
  2. Self-analysis: a self examination on paper, in private under supervision of the counsellor
  3. The client’s own choice and decisions: often shown under 1 and 2 already
  4. The counsellor’s analysis: an analysis of what the client revealed already:
    • Heredity and circumstance
    • Temperament and natural equipment
    • Face and character
    • Education and experience
    • Dominant interests
  5. Outlook on the vocational field
    • Lists of categories of industries and vocations
    • The conditions of success in specific vocations
    • General up to date information about industries
    • Apprenticeships systems
    • Vocational schools and courses available in your location
    • Employment agencies and opportunities
  6. Induction and advice for the client
  7. General helpfulness to fit into the chosen field

Even though I have slightly adapted the language, you can tell that his list may have fitted his era quite well but it would be drastically out of date for today’s reality. You can still see a strong genetic heritage in a lot of the techniques and theoretical underpinning in today’s practice.

Within this, the career counsellor was perceived as the expert, which is the direct opposite of today’s trend, where the client is the expert and the career counsellor is the facilitator. His perspective was typical for the time where class structures were still rigidly enforced and where professionals were admired and deferred to. His approach was positivist and betrays an almost mechanical way of choosing a career with a client fixed in aspic and and unchanging world of work.



The weaknesses of Parson’s theory for modern career practice in a 21st century society are clear for all to see. We live in a very different society to the one Parson’s theory was conceived in. Looking a bit harder, so are the strengths. In spite of urgent calls to rethink career counselling and guidance, ‘matching’ is still very much used in practice. It takes different guises from DOTS to personality based practice and tools such as Kudos, Startprofile and Fasttomato. However, I would propose they are used in a far less deterministic way and, if all is well, as a starting point for further work with the client. Kudos et al. are often something more entertaining to do for clients who just don’t want to know. For others, and more controversially, it’s a ‘go to’ tool for career guidance. This has the danger that it could lead to ‘lazy career guidance’ and easy and quick solutions to help someone tick a box. But if used with caution, care and consideration, matching tools can offer something back to the adviser that more contemporary approaches struggle to offer in the same way.

What do you think?

  • Would you be able to use Parson’s theory in your day to day practice? In what way, and what would it offer both you and your client?
  • What would be the limitations of differentialism for you and your clients?
  • What would be the dangers of using this?
  • If you think about matching tools, in what circumstances would they be a good idea?
  • When you think of the resources, in the broadest sense, available to you; what can you say ab out differentialism in that context?
  • How would this theory perform against Brown’s criteria?
  • Especially also compare this with a developmental theory and see what you think. Do we live in a static world or society? How well does this theory cope with change?
  • What does it not take into account about ‘the individual’?


Useful links:


  • Parsons F., 1909, choosing a vocation, Gay, London