Weird Science: Why do we like the taste of coffee?

Bitterness evolved as a natural warning system to protect the body from harmful substances - and by that logic, we should want to spit it out. Photo / 123RF

Why do we like the bitter taste of coffee?

Bitterness evolved as a natural warning system to protect the body from harmful substances – and by that logic, we should want to spit it out.

Yet, it turns out, the more sensitive people are to the bitter taste of caffeine, the more coffee they drink, and it's all because of a genetic variant.

"You'd expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee," said Marilyn Cornelis, assistant professor of preventive medicine at Northwestern University in the US and co-author of a new study.

"The opposite results of our study suggest coffee consumers acquire a taste or an ability to detect caffeine due to the learned positive reinforcement elicited by caffeine."

In other words, people who have a heightened ability to taste coffee's bitterness - and particularly the distinct bitter flavour of caffeine - learn to associate "good things with it".

Their study, which drew on data from 400,000 people in the UK, found those more sensitive to caffeine and were drinking a lot of coffee consumed low amounts of tea.

But that could just be because they were too busy drinking coffee, Cornelis noted.

The study also found people sensitive to the bitter flavours of quinine and of PROP, a synthetic taste related to the compounds in cruciferous vegetables, avoided coffee.

For alcohol, a higher sensitivity to the bitterness of PROP resulted in lower alcohol consumption, particularly of red wine.

"The findings suggest our perception of bitter tastes, informed by our genetics, contributes to the preference for coffee, tea and alcohol."

While taste had been studied for a long time, we still didn't know the full mechanics of it.

"Taste is one of the senses. We want to understand it from a biological standpoint."

Our funniest words?

Upchuck, bubby, boff, wriggly, yaps, giggle, cooch, guffaw, puffball, and jiggly: the top 10 funniest words in the English language, according to psychology experts. Image / NZ Herald

Upchuck, bubby, boff, wriggly, yaps, giggle, cooch, guffaw, puffball, and jiggly: these are the top 10 funniest words in the English language, according to psychology experts.

Researchers at Canada's University of Alberta have determined that there are two main kinds of predictors of funniness in words: those related to the form of the word and those related to its meaning.

"Humour is, of course, still personal," study co-author Professor Chris Westbury explained.

"Here, we get at the elements of humour that aren't personal; things that are universally funny."

The purpose of the study was to understand just what it was about certain words that made them funny.

The researchers began by statistically rating nearly 5000 words that had been rated on their humorousness in an earlier study.

"Our model was good at predicting which words participants would judge as funny, and to what extent."

The findings show there are two types of funniness predictors: form predictors and semantic predictors.

Form predictors have nothing to do with the meaning of the word, but rather measure elements such as length, letter and sound probabilities, and how similar the word was to other words in sound and writing.

For example, the study found that the letter "k" and the sound "oo" - as in "boot" - were significantly more likely to occur in funny words than in words that were not funny.

Semantic predictors were taken from a computational model of language and measure how related each word is to different emotions, as well as to six categories of funny words: sex, bodily functions, insults, swear words, partying, and animals.

"We started out by identifying these six categories," Westbury said.

"It turns out that the best predictor of funniness is not distance from one of those six categories, but rather average distance from all six categories.

"This makes sense, because lots of words that people find funny fall into more than one category, like sex and bodily functions - like boobs."

Climate change killed the super-rhino

Scientists think the "Siberian unicorn" survived a lot longer than we thought, and may have eventually died out because it was such a picky eater. Image / W. S. Van der Merwe/Natural History Museum

The world was once home to a rhinoceros that weighed up to 3.5 tonnes and boasted a single, enormous horn.

Now scientists think the Elasmotherium sibiricum, known as the "Siberian unicorn", survived a lot longer than we thought, and may have eventually died out because it was such a picky eater.

It was previously thought the animals became extinct around 200,000 years ago, but dating of remains from 23 individuals suggests it survived until at least 39,000 years ago, say the authors of a new international study.

They were also able to determine that the unicorns had a very limited diet, which may have contributed to their downfall.

This was most likely because of reduction in steppe grassland where it lived – due to climate change rather than the impact of humans.

Today there are just five surviving species of rhino, although in the past there have been as many as 250 species.

The Siberian unicorn, which roamed the steppe of Russia, Kazakhstan, Mongolia, and Northern China, was undoubtedly one of the most impressive.

Its final days were shared with early modern humans and Neanderthals.

"It is unlikely that the presence of humans was the cause of extinction," says co-author Professor Chris Turney, climate scientist at the University of New South Wales.

"The Siberian unicorn appears to have been badly hit by the start of the ice age in Eurasia when a precipitous fall in temperature led to an increase in the amount of frozen ground, reducing the tough, dry grasses it lived on and impacting populations over a vast region."