Decoded: The Science Behind Why We Buy

Next time you are at an airport and you look at the business book section you will find a vast selection of books promising to explain the science behind marketing and behavioural science and online, the selection is even more daunting. Unfortunately, after you have read a couple, many start to appear rather similar, recounting the same stories, experiments, and case studies. But every now and then you will come across a fantastic book that changes your perspective or opens your eyes to something new. Each month we will review one of these books, either a new release or something from the past, but outside of the mainstream behavioural science or marketing literature. This month: ‘Decoded: The Science Behind Why We Buy’ by Phil Barden 

‘Decoded' was first published in 2013 and for the last ten years it has been one of my top three ‘go to’ consumer psychology books. If someone asks for a book to introduce them to consumer psychology and they have no background in psychology, this is the book I recommend. When I heard that the second edition was published last month, I couldn’t wait to see what changes had been made. For those of you not familiar with the original book, ‘Decoded' is not your traditional marketing text. Rather than focusing on strategic marketing, it concentrates on tactics, and questions of execution. In simple terms, how you can use principles from psychology, cognitive neuroscience, and behavioural economics to create more effective adverts, packaging, and promotional campaigns.  

You may think that if you have already read books such as ‘Thinking, Fast & Slow’ or ‘Predictably Irrational’, that you have no need to read ‘Decoded’ especially if you have read the books that created (or at least popularised) the field of behavioural economics. But while both ‘Thinking, Fast & Slow’ and ‘Predictably Irrational’ do a fantastic job at showcasing how our decision-making deviates from the standard economic models, they don’t explicitly show how marketers can use this to our advantage. ‘Decoded' continues the journey that these books started but focuses on how these principles and psychological research can be used to effective marketing campaigns.   

But what really distinguishes ‘Decoded' from other similar books (and academic textbooks), is the balance the author strikes between science and practical application. With 25 years’ experience in senior marketing roles, he eloquently showcases how each psychological principle has been applied by businesses to impact their bottom line. This differs from most books where the authors tend to regurgitate the same stories and experiments from peer-reviewed papers. While the science may be robust, when you read the original papers carefully you typically find that despite the promising headlines, they don’t measure actual consumer behaviour, but instead focus on purchase intention – what participants (usually students) suggest they would hypothetically buy. To really bring the examples to life, ‘Decoded' includes numerous before and after photos, where you can see the original product packaging or advert and then view the redesign, incorporating the psychological principles. This before and after approach is likely to be highly valuable for both junior and mid-level marketers who may have a basic understanding of behavioural science but are unsure how they can apply it in practice.  

The examples in the book may be isolated case studies, and no statistician would want to generalise a finding from a sample of one, but it does help to reassure that the effects he describes generalise outside the lab (see ‘Time to get Real: What do some popular science books get wrong’, for a discussion about the challenges of lab-based studies.) However, the only potential downsides are that the majority of the examples discussed are British. From a personal perspective this is great, as most examples in marketing textbooks tend to be from the USA, but if you live in the USA or Europe, you might find some of the examples unfamiliar to you. However, even if you don’t know the brands, you’ll still be able to see how the principles apply.  

Barden is also not afraid to challenge the conventional wisdom within marketing – most notably when it comes to the role of emotion in both marketing and advertising. For the last ten years in the marketing press there seems to be the belief that for a campaign to be successful it must have an emotional appeal. However, Barden takes a structured look at the academic literature and discusses what do we really know about emotions in an accessible and readable way. Yes, ads that trigger an emotional response help us to remember the ad, but “If (the)emotional response is not linked to the brand, the ad might be remembered but not the brand because it is not instrumental in activating the emotional response.”. And despite what most marketers think, after reviewing 3,000 academic papers there is virtually no causal relationship between emotions and behaviour. In most cases, Barden argues, as marketers we should be far more focused on motivation and associations. Something, that should give most marketers pause for thought.  

As you may have guessed, this is an exceptionally well researched book, but it never feels like you are reading a textbook, nor is it a chore to read. The science is accurate, but always remains accessible and entertaining to read – no mean feat! However, if you are interested in learning more about any experiment, the book includes a detailed reference section so that you can easily find out more. This second edition is updated and reflects the new developments in consumer psychology that have occurred over the last decade, so even if you are familiar with the first edition, there is still plenty for you to learn.  

The book never loses its focus. Science is never discussed for the sake of science. Instead, this is a book designed to help you sell more, and at the end of each chapter there is a summary that provides a succent overview of what you should take away from each chapter and how marketers can apply this in the field. A nice touch and something I would like to see in more marketing books. If I was being critical, I would have liked to see a few more recent case studies included. Younger readers may be unfamiliar with some of the campaigns and adverts discussed, but that is a very minor point.   

To sum up, the second edition doesn’t disappoint. ‘Decoded' remains my go to recommendation for anybody who wants to learn more about consumer psychology and become an effective marketer, and as a Course Director for an MSc in Consumer Psychology, this book will remain at the top of the recommended reading list for the foreseeable future. 

 ‘Decoded', 2nd edition is published by Wiley in 2022 and is available to buy for £13.29