{"id":2876,"date":"2023-11-26T22:02:56","date_gmt":"2023-11-26T22:02:56","guid":{"rendered":"https:\/\/illuminated-text.com\/cb\/?p=2876"},"modified":"2025-07-29T20:25:38","modified_gmt":"2025-07-29T20:25:38","slug":"models-of-behaviour-change-e-g-tpb","status":"publish","type":"post","link":"https:\/\/illuminated-text.com\/cb\/models-of-behaviour-change-e-g-tpb\/","title":{"rendered":"Models of Behaviour Change (e.g. TPB)"},"content":{"rendered":"\n

(habitat threatened<\/a> by human behaviour – image credit<\/a>)<\/p>\n\n\n\n

The first thing to know about changing behaviour:<\/h4>\n\n\n\n

Behaviour is important. What we do matters. It matters for our health (how we eat, sleep, exercise, and socialize#up), it matters for companies (will people buy our thing?) and for countries (how many people will work, consume, pay taxes, vote for good leaders) and the world (wars and global climate change all depend on our behaviour).<\/p>\n\n\n

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#down. Loneliness (which is a psychological state, not the number of people in a room with us) is as bad for our health as smoking<\/a> 15 cigarettes a day<\/pre>\n<\/div><\/div>\n\n\n
Behaviour is important but also often very difficult to change. We humans are very prone to settling into patterns: we tend to be very stable in what we eat and wear, the transport we use, the exercise we do (and don’t) get, the things we do for fun, etc. Even when our lives feel like they are changing we are still usually doing a lot of the same things – it’s just that we naturally and sensibly pay more attention to the parts that are new.<\/p>\n\n\n\n
If you’ve had a time in your life when nearly everything has changed it was probably a major transition: moving countries, starting a new job or school, or being in a really difficult place socially or psychologically.<\/p>\n\n\n\n
Changing behaviour is hard, but lots of people spend a lot of time, energy, and money trying to do it: marketers, health and environmental campaigners, politicians, etc (“buy my thing, eat healthier food, use less polluting transit, vote”, etc)… But they are often frustrated with the small returns on their efforts. The good news is that sometimes many small changes can add together to make a big difference, but the bad news is that sometimes they don’t.<\/p>\n\n\n\n
Models of behaviour change:<\/h3>\n\n\n\n
Because changing behaviour can be so important, quite a few models have been developed to help predict when and how this happens.<\/p>\n\n\n\n
We will focus on one family of such models#up. It has several well-known models, with names such as the “Theory of Reasoned Action”, “Uses and Gratifications Theory”, and the “Technology Acceptance Model” <\/span>, but we will focus on the best known of them all, the Theory of Planned Behaviour <\/span>, or “TPB”. <\/p>\n\n\n
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#down. Just for breadth, we'll show you what another kind looks like, too, at the bottom of this page<\/a><\/pre>\n<\/div><\/div>\n\n\n
Once we’ve learned the TPB, we’ll show you quickly how it compares<\/a> to some of its cousins – the models in this family are so similar that understanding one should make the others easy to pick up, if you ever need them. <\/p>\n\n\n\n
The Theory of Planned Behaviour<\/h1>\n\n\n\n
This model identifies three main influences on how and why people make decisions: attitudes, subjective norms, and perceived behavioural control. It also has a specific formula for how these ingredients combine together. It looks like this:<\/p>\n\n\n
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\"Boxes<\/figure>\n<\/div>\n\n\n
All clear? Moving on then!<\/p>\n\n\n\n
(we joke!)<\/p>\n\n\n\n
Let’s unravel this from bottom to top.<\/p>\n\n\n\n
Behaviour, in the bottom rectangle, is the final outcome that this model tries to predict. For our textbook purposes this behaviour is probably some form of consuming, but it doesn’t have to be.<\/p>\n\n\n\n
The box in the middle is for “intentions”. The model claims that our intentions will predict our behaviour. This tells us two things:<\/p>\n\n\n\n
1) the model doesn’t claim that intentions and behaviour are the same thing. This will be familiar to everyone who has intended to go to eat a salad then go to the gym, yet who instead ended up on the couch with a plate of fries. The claim is that our intentions tend to guide our behaviour, but not that they are automatically successful at doing this.<\/p>\n\n\n\n
2)  This is a model of what people intend to do, not of their habits or impulses. It’s not that we don’t have habits, only that this model doesn’t try to explain them. It is, after all, the theory of planned<\/strong> behaviour; It is very much about system 2.<\/p>\n\n\n\n
The three rectangles at the top are labelled “attitude”, “subjective norms”, and “perceived behavioural control”. Let us allow Ajzen himself to define them for us (complete with American spellings):<\/p>\n\n\n\n
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Attitude towards behaviour<\/strong><\/p>\n<\/span><\/cite><\/blockquote>\n\n\n\n
“The degree to which a person has a favorable or unfavorable evaluation or appraisal of the behavior in question.”<\/p>\n<\/div>\n\n\n\n
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Subjective norm towards behaviour<\/strong><\/p>\n<\/span><\/cite><\/blockquote>\n\n\n\n
“The perceived social pressure to perform or not to perform the behavior.”<\/p>\n<\/div>\n\n\n\n
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Perceived behavioural control towards behaviour<\/strong><\/p>\n<\/span><\/cite><\/blockquote>\n\n\n\n
“The perceived ease or difficulty of performing the behavior… it is assumed to reflect past experience as well as anticipated impediments and obstacles.”<\/p>\n<\/div>\n\n\n\n
In other words, if the question is whether you will form an intention to buy a salmon roll for dinner, then this decision might be shaped by:<\/p>\n\n\n\n
Your attitude:<\/strong> Do you think that they are good things to eat? Yummy, perhaps, and healthy? Or bland and too fancy?<\/p>\n\n\n\n
Your subjective norms:<\/strong> Is this the sort of thing that I’m supposed to do? Would people care? Think it is interesting or pretentious? Reference groups often provide strong cues here.<\/p>\n\n\n\n
Your perceived control:<\/strong> Can I afford it? Is it cheap? Can I find a place that makes a good one?<\/p>\n\n\n\n
<\/pre>\n\n\n\n
You will be reassured to know that there is a lot of research suggesting that these 3 factors, taken together, do a fairly good job of predicting people’s actions.<\/p>\n\n\n\n
Also note, the models shows a dotted line from control to behaviour. This is meant to suggest that sometimes we can’t do a behaviour purely because the situation does not allow it as an option, no matter our intentions. This is not the model focuses (hence the line being drawn only in dots), but the model acknowledges that this does happen.<\/p>\n\n\n\n
FAQ: Do all three matter in every case?<\/h5>
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Not at all. <\/p>\n\n\n\n
In some cases the only thing that matters is your attitude towards an object – this is probably the case for a lot of consumption. For instance, if you are buying a portable USB flash drive, the only real consideration is likely to be how well you think it will work. <\/p>\n\n\n
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You probably aren’t too worried about what people will think, or how possible it is to get (credit<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n
In other cases you might consider any two of these forces (“if I can get the right new sweater for the office party, people would probably like it”), or all three of them together.<\/p>\n<\/div><\/div>\n\n\n\n
So far so good… But if you are a cynic you might be wondering if there is anything really new here. We already know that people liking things and culture matter, so are we just making a big checklist here?<\/p>\n\n\n\n
Partly yes, but the theory does also have some more handy things to say. <\/p>\n\n\n\n
Let’s draw a bigger picture:<\/p>\n\n\n
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\"Summary
The Theory of Planned Behaviour<\/figcaption><\/figure>\n<\/div>\n\n\n
Don’t worry, we’ll walk you through it.<\/p>\n\n\n\n
Attitudes, norms, and control: What are they made of?<\/h2>\n\n\n\n
TPB has some pretty specific ideas about what goes into making up people’s attitudes, norms, and perceived control, but this is where the explanations gets complicated enough that it is helpful to walk through an example.<\/p>\n\n\n\n
So let’s say that you are deciding between two choices for where to go on holiday. Option 1 is a friend who has invited you to an island in the Maldives, and option 2 is to hop on a train across the UK (let’s say you start in Manchester), to an English beach in Skegness, Lincolnshire.<\/p>\n\n\n\n
Option 1<\/strong><\/p>\n\n\n
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An island in the Maldives, 750km south of India (credit<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n
Option 2:<\/strong><\/p>\n\n\n
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\"An
Skegness, Lincolnshire, UK. A 6-hour train ride west of Manchester (iStock<\/a>)<\/figcaption><\/figure>\n<\/div>\n\n\n
Which does the TPB say you will choose? Let’s look at how each of its 3 ingredients works:<\/p>\n\n\n\n
Composition of attitudes:<\/h3>\n\n\n\n
Recall that your “attitude” towards a thing is how much you like it#up. There’s a very old idea that our attitude towards a thing are heavily influenced by our beliefs towards it (e.g., “I like tofu because I believe it doesn’t taste of much, but is better for the planet than eating meat”). This is useful because it suggests that you can work out why people have the attitudes that they do, and then how to change them (i.e., by changing their beliefs).<\/p>\n\n\n
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#down. At least, that's what psychologists mean. It has other uses in normal English (\"he has a good attitude\", etc)<\/pre>\n<\/div><\/div>\n\n\n
Before we explore how TPB uses this idea, there are some obvious questions for us to ask:<\/p>\n\n\n\n
First question: Is it really true that attitudes are made up of beliefs? <\/p>\n\n\n\n
The evidence suggests that this they are… although (as with most things in psychology) they are not100% of the story; Sometimes we have a positive attitude towards a thing for pretty random reasons (it just because it reminds us of something else, or we had a good experience with it years ago that we’ve mostly forgotten). But changing people’s beliefs about things does seem to change their attitudes towards it.<\/p>\n\n\n\n
Second question: How do you convert “I have beliefs about a thing” into “I have feelings about that thing”?<\/p>\n\n\n\n
TPB has a formula for how to combine beliefs that can be written down as a mathematical formula. We’ll show this to you soon, but first we’ll describe it in normal English and show you what how it might work for our holiday-choosing example.<\/p>\n\n\n\n
If you list it out step by step, the TPB approach to attitudes works like this:<\/p>\n\n\n\n
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  1. Identify 2-4 of your most salient beliefs about each holiday option.\n