If you had a stressful childhood, you’re more susceptible to impulse buying later in life. Not just unhealthy snacks, but also healthy things, Bob Fennis found out. And we can use that.
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Door Christien Boomsma

2 June om 12:16 uur.
Laatst gewijzigd op 27 November 2023
om 16:57 uur.
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By Christien Boomsma

June 2 at 12:16 PM.
Last modified on November 27, 2023
at 16:57 PM.
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Christien Boomsma

Achtergrondcoördinator en wetenschapsredacteur Volledig bio »
Background coordinator and science editor Full bio »

Are you easily swayed by that limited edition ice cream that your local supermarket just happens to have on sale? Or do you always end up buying a family-sized bag of crisps because it’s on offer this week and won’t be for much longer? 

It’s possible you had a stressful childhood. Perhaps your family didn’t have much money; perhaps your parents went through a nasty divorce; or perhaps it was even worse, and you grew up with your parents fighting a lot, abuse, or other nastiness. 

At any rate, it’s left you feeling like nothing in life is certain, and the future is anything but rosy. Whether you’re aware of it or not, whether your parents had the best intentions or not, that’s simply how it works. ‘That feeling’, says UG marketing researcher Bob Fennis, ‘impacts the rest of your life as well. It causes you to develop what’s known as a fast life history, which means you’re very susceptible to rewards and impulse buying. You want things right now, because you don’t know if they will still be there tomorrow.’

Limited availability

That means you’re extra susceptible to scarcity cues: signals telling you about the limited availability of a product, like that limited edition ice cream or those crisps that are on sale. During a study he recently wrote an article about for Food Quality and Preference, Fennis found out that the same principle applies to healthy products.

That’s where it gets interesting. 

After all, nothing is more difficult than convincing people to be healthy. The government keeps trying, setting up countless campaigns, but to no avail. ‘Trying to get people to do a 180 on their lifestyle is extremely difficult. These campaigns pretty much all have a zero-percent success rate.’ 

These campaigns pretty much all have a zero-percent success rate

This makes sense once you realise that most of your decisions concerning food, purchases, and behaviour are unconscious. Smart marketing experts influence people by using a weakness they don’t even know they have. No government campaign can compete with that. 


On top of that, people with a fast life history tend to be on the lower end of the socio-economic spectrum. This also happens to be a group that has a lower income and education, and suffers from an increased rate of obesity, diabetes, smoking issues, and cardiovascular disease. 

‘You can tell these people they need to radically change their lives and eat broccoli instead of french fries or drink water instead of beer’, says Fennis, ‘but it simply isn’t going to happen. Theirs is a physiological make-up that doesn’t just change.’

It’s smarter to steer a different, more subtle course; one that doesn’t fight people’s impulses but uses them. It’s easier, cheaper, and has a greater chance of success. ‘Going with the flow just works better’, says Fennis. ‘Impulse buying doesn’t have to be unhealthy.’

Cool grapes

He studied this by presenting approximately a hundred Zernike students with a choice. In the study, the students tried out grapes. ‘In half of the cases, we presented these grapes as though they were really cool’, says Fennis. ‘We said they belonged to a special kind that could only be harvested once in a while.’ The other half of the students were told the grapes were just regular old grapes.

We said the grapes were really special

After the students tasted the grapes, they were presented with a questionnaire aimed at determining whether they had a fast life history – and whether they had the family life to match – or a slow life history, characteristic of people who had a quiet and balanced childhood. ‘People with a slow life history have opposite reactions’, says Fennis. ‘They’re not nearly as susceptible to impulse buys. They’re also more likely to buy things that are readily available. They take fewer risks.’

‘The “slow” people didn’t respond to the scarcity cue – the information that the grapes were special. But the “fast” people tended to eat more grapes if they’d been labelled as rare’, Fennis observed. 


‘Fast’ and ‘slow’ are relative terms, obviously. There are so many different degrees between someone who spent their childhood in a war zone and someone who was raised in a mansion. But the differences were observable. Just like the effects. Fennis saw the same results in a larger online study distributed throughout Europe. 

‘Of course, everyone is susceptible to a sale’, he acknowledges. ‘But think of it as tug-of-war: when someone with a slow life history strategy walks past a sale offer, the devil on their shoulder might win one out of five times. In people with a fast life history strategy, the devil wins four out of five times.’

These people love mayonnaise even more 

That’s not moral weakness, nor a judgement. People usually don’t even buy things because of the supposed financial gains. ‘It’s just the way they make decisions.’ What’s more, says Fennis: ‘There are even signs that people with a fast life history strategy, who are more susceptible to rewards, react more strongly to sensory stimuli.’ What does the cheese look like? How fresh are the crisps? ‘Everyone loves mayonnaise’, he says. ‘But they love it even more.’


Fennis thinks the industry can use this by giving healthy alternatives a scarcer, exclusive image. He doesn’t expect the current, liberal government to do much about it. ‘Just look at how long it took before we got those deterring images on cigarette packs.’  But he thinks the information he learned has commercial value as well. ‘I think a food manufacturer like Unilever, which wants to be more sustainable and healthier anyway, could be convinced to do something like this.’

They could come up with exclusive diet products, flavoured water, and mini tomatoes in a fancy container. ‘No matter how you spin it, those are still chock full of antioxidants.’

Translation by Sarah van Steenderen