Do you have a favorite chocolate bar?

Ask that question in the UK, and the answer will often be the same.

Across the Atlantic Ocean, there is a huge chocolate company that have dominated the UK candy market for generations. In Birmingham, in the middle of the UK, Cadbury have been manufacturing chocolate for nearly 200 years.

And their signature chocolate bar, Cadbury Dairy Milk, is central to their popularity, its rich purple packaging and smooth milk chocolate synonymous with sweet treats across the British Isles.

However, with time comes change and for many reasons – modernisation and profitability among others – Cadbury recently launched a redesign of their classic Dairy Milk bar.

The recipe, the company promise, has stayed the same; all they’ve done is slightly alter the shape of the bar. Instead of the traditional square chunks, Cadbury’s Dairy Milk is now slightly rounder, with the pieces of chocolate having smooth corners instead of pointy edges.

But they’ve not changed the formula, so the taste should be just the same, right?

Well, not exactly. According to many consumers, their beloved chocolate bar now tastes sweeter than it did before.

To determine how exactly this is possible, given the recipe hasn’t changed, academic Charles Spence from Oxford University probed further into the science behind the shape of our food.

And what he has found is mind-blowing.

In fact, Spence argues in a paper published in the academic journal Flavour, the changed taste that chocolate-lovers are experiencing when they try the new Dairy Milk bar has very little to do with the actual taste; rather, it has more to do with a certain element of psychology we attribute to the appearance of our food:

“I suggest that this furore can perhaps be explained with reference to the literature on shape symbolism.

The generalization that has now been documented across a range of food and beverage products is that sweetness is associated with roundness while bitterness is associated with angularity.”

So people are just reacting to the newly rounded chocolate, believing that it is sweeter because its edges are no longer pointy.

But when we were hunter-gatherers most of our food was round, so where does this assumption come from? It must be a new thing, right?

Well, not entirely. Spence goes on to explain why, in an evolutionary sense, we may associate angular foods with bitterness:

“One plausible suggestion is that angularity, bitterness, and carbonation might be associated because they all have some link to danger. Angular shapes are potentially weapons, and our brain’s fear circuits have been shown to light up within a few 10’s or 100’s of milliseconds of seeing an angular shape.

Bitterness and carbonation are also, evolutionarily at least, danger signals that would have been associated with foods that were potentially poisonous (bitterness) or overripe (carbonation).”

So even though we might be fans of bitter flavors now, in the past they were a sign of danger, of poisonous foods or usually-safe foods that were no longer suitable for consumption.

Rounder foods, on the other hand, are associated with safer and more comforting objects. You’re not going to get stabbed by a pillow, after all. Therefore, Spence explains in his paper, as sweetness was usually a sign that a food was safe to eat, we do not have any of the evolutionary danger responses to sweet foods:

“People are known to associate sweetness with roundness and angularity with bitterness and, hence, making a traditionally rectangular food rounder may be expected to alter the perceived taste by priming notions of sweetness in the mind of the consumer.

This can happen both as a result of shape symbolic priming of taste qualities as stressed here, but possibly also as a result of the different sensory experience of the rounder chocolate within the oral cavity itself.”

In the case of Dairy Milk, people were incensed by the change from angularity to roundness. This may seem counterintuitive, since the shape is – at least in an evolutionary sense – much safer.

But for the people of Britain who, in modern society, are not endangered by the corners of their candy, this is likely as much a traditional thing.

The thing that they love, that generations before them have loved, has changed. And change could also signal danger.

But most of all, they have noticed the difference in the shape of their beloved chocolate bar; their perception of this new roundness, when interpreted through the lens of Spence’s research, suggests to them that the same chocolate is sweeter than it ever was before.

As unlikely as it may seem, the shape of your food really can change the way it tastes – or at least the way you think it tastes, as Cadbury discovered to their detriment!

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