text on pavement: passion led us here

Changing interests

(How) do vocational interests develop over time? A conceptual analysis.

In this article, Bart Wille and Filip De Fruyt share some insights into the matter of adult vocational interest development. These ideas were recently published as a chapter in the new book on vocational interests in the workplace edited by Professors Christopher Nye and James Rounds. Wille en De Fruyt developed a theoretical framework to structure their ideas about how vocational interests might change over time, after people have entered the labor market.


In this article, we want to share some of our insights into the matter of adult vocational interest development. These ideas were recently published as a book chapter in a new book on vocational interests in the workplace edited by Prof. Christopher Nye (Michigan State University) and Prof. James Rounds (University of Illinois at Urbana-Champaign), two leading academics in the field of vocational interests. Endorsed by the Society for Industrial and Organizational Psychology board, this book is a valuable resource for researchers, professionals, and educators in the field of human resources, organizational behavior, and industrial or organizational psychology.

book cover vocational interests in the workplace

Bart Wille and Filip De Fruyt, both Ghent University, were invited to contribute to this book with a chapter on adult interest development. This was a great opportunity to develop and share some new ideas on how vocational interests might change over time, after people have entered the labor market. We are excited to share some of these ideas with you through this article.


“I loved my job when I started it ten years ago, but for a while now I simply don’t get enough satisfaction out of it anymore”

A summary of the ideas

After thinking about these questions thoroughly and based on the scarce empirical research available on this topic, we developed a new theoretical framework to structure our ideas. We used the well-known principle of Person-Environment Fit to guide the theory development. The resulting model is displayed below.

visual representation of transactional model of PE fit

Yes, we are fully aware that there are a lot of boxes and arrows in this scheme. Let us walk you through some of the main ideas and illustrate you how the model works.

Personal development and career development go hand in hand

The basic logic behind the model is that people’s personal development and their career development do not happen in isolation, but instead interact with each other over time. This is the ‘transaction’-part of the model.
How you develop as a person (your personality traits, vocational interests, values etc.) has an influence on how you develop professionally (choice of your career, your effectiveness and satisfaction at work etc.) and vice versa! This also means that professional development can only be fully understood when people’s personal development is taken into account. Multiple life domains overlap and interact. 
This overlap in particular between the characteristics of you as a person and the characteristics of your professional environment is captured in this model by an intersection. In the model, this is represented by the box with the curly bracket.  It is in this intersection that people can feel authentic at work (‘what you do aligns with who you are’) and helps you to identity with work (‘my work is a part of how I define myself’). This intersection is what we mean by person-environment fit and it plays a crucial role in our theory on adult interest development.

P-E fit is a sweet spot

Based on decades of research on the conditions that make people happy and successful across different life domains, we concluded that Person-Environment (P-E) fit must be one of the driving forces behind interest development. Modern theory on life-span development explicitly states that attaining a satisfying level of fit or ‘congruence’ between one’s personal attributes and one’s environment is a fundamental life task and an indicator of developmental success. 
This is just a complex way of saying: it really helps you when you can do stuff that you enjoy doing and that you are good at. In short; P-E fit acts as an incentive, both for the individual and the environment. For the individual, fit is a source of satisfaction and fulfillment. For the environment, fit means that people are more productive.  

A series of fit dynamics 


Let’s focus on manipulation first. Work can change either towards or away from one’s personal attributes. This leads to the following two manipulation effects in the model:


Gravitation reflects changes in work in the direction of person-characteristics. In other words, work changes and becomes more aligned with one’s defining traits. The intersection widens and the level of P-E fit thus increases. The typical example is someone switching to a new job which is more closely aligned with one’s interests. This might be something Lola-users are looking for. An alternative example might be ‘changed work content’ in the same job: You ask your boss to do more tasks in line with what you are good at or like.
We also speculated on what this could mean for the direction and nature of interest development. One hypothesis is that gravitation could lead to interest specialization, where people narrow down their interest profile and specifically deepen those preference fields that align with what they currently are doing. Most of us know such a narrow-minded specialist that fits this description, right? 


Diversification is the term used to describe changes in work away from one’s personal attributes. Schematically, this means that the intersection between person- and work-characteristics shrinks and P-E fit decreases. Most of us know someone who ended up in a job that really did not speak to the person’s interests. Maybe it’s even you who is in this situation!?
One relevant question in this context is: what happens then to one’s interest levels? For instance, can one learn to ‘grow’ an interest in work activities that one initially did not like at all? To what extent? Under which conditions? We can speculate. But honestly, at this point there’s simply not enough empirical data to draw any firm conclusions. 


Changes can also take place with respect to the person. Depending on the direction of this change, the model distinguishes between two types of transformation effects: Socalization and Alienation.

To conclude 

This is basically how the model works. It is a theoretical exercise, so it is normal that it all sounds a bit abstract to you. Also, because it is a model, it's normal that you have the feeling that it simplifies a number of phenomena that are in reality far more complex. But that is what theoretical models are supposed to do. At best, it may provide you with some initial insights into the processes going on when looking at people and how they develop over time while crafting a career.

Want to know even more? Send us an email to receive a preprint of this book chapter.

Wille, B. & De Fruyt, F. (2019). The development of vocational interests. In C. D. Nye & J. Rounds (Eds.), Vocational Interests in the Workplace: Rethinking Behavior at Work. SIOP Organizational Frontiers Series.