Changing Behaviour: Set in Plaster or Malleable as Plastic?

Psychology 101: The 101 Ideas, Concepts and Theories that Have Shaped Our World - Adrian Furnham 2021

Changing Behaviour: Set in Plaster or Malleable as Plastic?

If there is something that we wish to change in the child, we should first examine it and see whether it is not something that could be better changed in ourselves. (Carl Jung, 1956, Collected Works)

Even God cannot change the past. (Agathon, quoting Aristotle, Nichomachean Ethics)

The issue of what beliefs and behaviours we can and can’t (easily) change is fundamental to psychology. There are many self-help books that promise to provide the answer of how to change behaviour, from the ’curing’ of addictions to general health and happiness. Many offer simple solutions to complex psychological phenomena and processes and often make claims that are not supported by science, namely disinterested, peer-reviewed, empirical research.

We know that all diets fail because people stop dieting. Permanent weight loss requires a lifestyle change. The question is how easily this is done. Most people know how difficult it is just to give up non-addictive habits.

Equally there is a huge ’change industry’ driven by individuals’ and organizations’ desire to change.

In an attempt to ’review with unflinching candour the effectiveness of most different kinds of treatment for the major psychological disorders’, Seligman (2007: p.xi) provided some facts about psychological change. In his book he reviewed the changeability of 16 disorders including sexual preferences, identities, orientations and dysfunctions. He also provided ten ’facts about change’:

1 Panic can be easily unlearned, but cannot be cured by medication. Dieting, in the long run, almost never works. The sexual ’dysfunctions’ — frigidity, impotence, premature ejaculation — are easily unlearned. Kids do not become androgynous easily.

2 Our moods, which can wreak havoc with our physical health, are readily controlled.

3 No treatment is known to improve on the natural course of recovery from alcoholism.

4 Depression can be cured by straightforward changes in conscious thinking or helped by medication, but it cannot be cured by insight into childhood.

5 Homosexuals cannot become heterosexual.

6 Optimism is a learned skill. Once learned, it increases achievement at work and improves physical health.

7 Reliving childhood trauma does not undo adult personality problems.

There are debates in various areas of psychology about how to change individuals, as well as groups and organizations as a whole.

In personality theory there are debates between those who argue that people do change (considerably and significantly over time) and those who suggest they do not. This is sometimes called the plaster vs. plastic hypotheses with the former advocates suggesting that personality traits change very little over time, while the latter argue that significant, systematic and explicable changes can and do occur.

Over the years the ’plaster’ hypothesis of little or no change had been replaced with the ’plasticity’ hypothesis of possible change. It seems now that many trait theorists recognize that traits can and do change over time, though there remains debate about which traits change least and most, why and by how much.

Equally there were studies in clinical psychology that examined theories of, and evidence for, change and ’cure’ as a function of therapy. In a study comparing laypeople and clinical psychologists, researchers found clinicians much less optimistic and more sceptical about the efficacy of therapy and the prognosis of personal problems compared to laypeople. Thus therapists believed that while phobias, anxiety attacks and sleep disorders had a good prognosis and autism, dementia and drug dependence a poor prognosis, laypeople were much more optimistic overall about all 36 problems presented. There is also a debate about whether intelligence can change; that is whether people can become more intelligent.

This is a topic of considerable academic debate with some arguing that people can, and others that people cannot, sustainably increase their intelligence. Thus Kuszewski (2011) concluded: ’Fluid intelligence is trainable. The training and subsequent gains are dose-dependent, meaning, the more you train, the more you gain. Anyone can increase their cognitive ability, no matter what your starting point is. The effect can be gained by training on tasks that don’t resemble the test questions.’


All coaches, counsellors and therapists know that people change only if they want to. They cannot be forced or even bribed. They must really want change. So why would employers want seriously to change their lifestyle, philosophy and management style? There are half a dozen common causes:

1. Loss: Loss of a significant person (parent, spouse, and/or child). That can, for them, change the purpose of life. All plans, hopes and dreams go with them. The situation requires re-appraisal.

2. Illness: This is most often caused by stress and habit disorders.

3. Insoluble Conflict: This as much outside as inside the workplace. Relationships are both the major source of support and stress.

4. Unfulfilled Dreams: Most of us have career dreams, expectations and fantasies. As time ticks by it becomes apparent that the hope will probably never be fulfilled.

5. Inauthenticity: Most people have to be ’someone else’ at work. Work requires serious sacrifice of time commitment etc.

6. Trauma: This may be of a life-threatening kind or not. Being involved in an accident; being robbed of precious possessions; a brush with the law.

There are certain criteria or markers of what one might call change-readiness.

First, their psychological insight and curiosity, mainly about themselves but also about others. This is not an invitation to a narcissistic, self-indulgent fest of self-justification. It is about trying to see connections between thoughts, emotions and behaviour in one’s past and current life.

Second, emotional awareness and management: this is being affectively literate; able, courageous and willing to talk about true emotions. More than that, it is about how to deal with them once the mud at the bottom of the pool is disturbed.

Third, the capacity for self-disclosure: that is to open up to others, talk more openly and in a less guarded way about fears, beliefs and guilty secrets.

Fourth, receptivity and adaptability to the observations of others. This is about really listening to what has been said (usually many times).


Ardelt, M. (2000). Still stable after all these years. Social Psychology Quarterly, 63, 392—405.

Furnham, A., Wardley, Z. & Lillie, F. (1992). Lay theories of psychotherapy III. Human Relations, 45, 839—58.

Kuszewski, A. (2011). You can increase your intelligence. Scientific American, March 7, 1—8.

Seligman, M. (2007). What you can change…and what you can’t. London: Nicholas Brealey.