Can adults change their behaviour? (5 models/theories)

This blog post aims to answer the question, “Can adults change their behaviour?” and explore the various dimensions of personality that influence behaviour and change in order to help understand the answer. 

Can adults change their behaviour?

Yes, adults can change their behaviour according to the following 5 models/theories –  

  • The theory of planned behaviour/reasoned action.
  • Social cognitive theory.
  • Transtheoretical model.
  • Information–motivation–behavioural skills model.
  • Behaviour change wheel & COM-B model.

These 5 models/theories of behavioural change will be discussed in further detail below after taking a deeper look at what behavioural change means.

What is behavioural change?

The goal of behavioural change is to permanently modify habits and behaviours. 

According to the majority of studies on health-related behaviours, even little adjustments can have a big impact on a person’s health and life expectancy (Davis, Campbell, Hildon, Hobbs, & Michie, 2015). 

Other people’s health may be negatively impacted by these modifications (Swann et al., 2010).

Examples include –

  • Smoking cessation
  • Reducing alcohol intake
  • Eating healthily
  • Exercising regularly
  • Practising safe sex
  • Driving safely

Other behaviours that are the focus of change efforts include those that have an adverse impact on the environment, such as –

  • Littering
  • Leaving lights on
  • Not recycling

Changing some behaviours might lead to an increase in well-being. Examples include –

  • Reducing procrastination
  • Incorporating regular self-care activities
  • Being more assertive at work
  • Going to bed earlier
  • Practising mindfulness

These are only a few illustrations of behaviour modifications that many people have attempted at some point in their life. While some modifications could be simple, others might be very difficult.

What are these 5 models/theories of behavioural change?

The theory of planned behaviour/reasoned action.

In the 1970s, Fishbein and Ajzen created the notion of reasoned action. According to this idea, behaviours are the result of intentional behaviour, and intentional behaviour is impacted by one’s mood and the accepted societal standard (Madden, Ellen, & Ajzen, 1992).

This suggests that the greater a person’s purpose to change their behaviour will be and the more likely they are to succeed in doing so, the more positive their attitude toward altering their behaviour is and the more others are practising the desired behaviour or supporting the behaviour change.

Ajzen expanded on this concept in the 1980s by including perceived behavioural control as a factor in intention and occasionally as a direct effect on behaviour (Madden et al., 1992).

A person’s perceived behavioural control is determined by how confident they are in their ability to carry out the behaviour and by whether they think they can get over obstacles and hurdles. 

The idea of planned behaviour, an expanded version of the theory of reasoned action, explains more diversity in behaviour change (Madden et al., 1992).

Social cognitive theory.

Bandura’s social learning theory, which claimed that many behaviours are learnt through seeing others in our social context, was expanded into the social cognitive theory in 1986. (Bandura, 1999).

We must pay attention to the behaviour that is being modelled, retain it, and imitate it in order for us to acquire that behaviour. For doing this, we could receive rewards or punishment, which increases or decreases the probability that we would repeat the behaviour. 

However, Bandura agreed that adopting a behaviour involves more than just this. He developed his theory to take into account the biological, emotional, and cognitive aspects of the individual. 

This comprises a person’s own resources and skills, perceived self-efficacy (ability to carry out the behaviour), expectations of the costs and advantages of altering their behaviour, and expected opportunities and impediments that might either assist them or impede them.

According to Bandura, our perceptions of our own abilities and our expectations for the results of those efforts are key factors in deciding how we behave. 

Our social environments can help or hinder our aims by presenting possibilities or imposing limits, which in turn can impact how effective we feel about ourselves and how we expect things to turn out in the future (Bandura, 1999).

Transtheoretical model.

This concept, often known as the phases of transformation, appears the most in the literature. Prochaska and DiClemente created the transtheoretical paradigm in the late 1970s, which proposes six stages of behaviour change (Prochaska, 1979; Prochaska & DiClemente, 1982).

It is easier to give specific solutions for a stage when health practitioners, coaches, and therapists are aware of the stage a person is in.

The six stages of change are –


The person does not plan to alter their behaviour. They could not be aware of the effects of their behaviour or lack faith in their capacity to change, often as a result of earlier failures.


Within the upcoming six months, the person wants to alter their behaviour. They can see the advantages of changing, but they are also acutely aware of the drawbacks and difficulties that may keep them in this stage.


Within the next month, the person wants to alter their behaviour. They often have some type of plan in place and have already taken some actions, such as joining a support group, purchasing a self-help book, or hiring a coach, among others.


Within the recent six months, the person has significantly altered their behaviour, which has had a different impact on their health and/or wellbeing.


Although they are not investing as much time and energy in this as they were during the action stage, the person is still changing their behaviour enough to prevent relapse.

Relapse can occur at any stage up to and including this one, going back to any of the earlier stages in the model. Most typically, people go back to thinking about or getting ready for another attempt at modifying their behaviour (Prochaska & Velicer, 1997).


The person no longer feels the need to rely on their previous coping mechanisms and is secure in their capacity to maintain this shift. This last stage will be difficult for many people to achieve.

Information–motivation–behavioural skills model.

Fisher and Fisher (1992) developed this model after studying the literature on modifying AIDS-risk behaviour. They suggest three main aspects that drive behavioural modification –

  • Information about the behaviour.
  • Motivation to perform the behaviour.
  • Behavioural skills to perform the behaviour.

Both unconsciously learnt knowledge and instinctive ideas regarding behaviour are considered to constitute information. 

Personal motivation, or the desire to alter behaviour for oneself, as well as social motivation, or the desire to alter behaviour to fit into the social context, are both examples of motivation.

Information and motivation impact behavioural skills, which include objective skills and subjective self-efficacy. Information, motivation, and behavioural abilities all work together to affect behaviour.

As a helpful professional, you may influence your client’s behaviour by giving them more knowledge, assisting them in discovering their motivation, improving their objective behavioural abilities, or boosting their sense of self-efficacy.

Behaviour change wheel & COM-B model.

A behaviour change wheel was developed in 2011 by Michie, van Stralen, and West using several behaviour change frameworks. The purpose of this was to offer direction for behavioural therapies and policymakers based on the available data.

Three conditions—capability, opportunity, and motivation—are involved in the hub of this wheel, which is the component that matters the most to us.

  • The capability to carry out the behaviour encompasses both the physical and psychological capacity, as well as having the required information and abilities.
  • Opportunity is about the circumstances that surround a person and either enable or disallow certain behaviours.
  • Motivation, which includes habits, emotions, and ideas, is the need and energy to carry out a behaviour.

The COM-B model, which combines these elements, theorises that opportunity and capacity drive motivation while all three aspects influence behaviour. Any of these areas might be improved to aid your customer in changing their behaviour.

Conclusion – 

This blog post aimed to answer the question, “Can adults change their behaviour?” and reviewed the various dimensions of personality that influence behaviour and change to help determine if adults can change their behaviour. Please feel free to reach out to us with any questions or comments you may have.

References –

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