Intuitively, we can relate to this: as we get closer to completing a goal we can feel more motivation to complete it. Getting close to the last piece of a puzzle, the last clue of a murder mystery or escape room, the final chapter of your book (perhaps), the final kilometre of a marathon, or as you find you need just one more stamp to get a free coffee, being so close to our goal can give us a motivation lift to get to the end. It has a name:  the goal-gradient effect*.

In the example in the sketch, Oleg Urminksy and coauthors found that as people approached the final stamp towards a free coffee they were more likely to pick up the rate of buying coffees. And when issued with the new card, the coffee buying rate went back down again. They also found that it wasn't so much the absolute 'distance' from a goal, but the perception of distance. So, people who started out on a 12 stamp card with 2 stamps already complete tended to complete the card faster than the people who had a 10 stamp card starting empty even though it was the same number of stamps to the goal.

Read more in Katy Milkman and Kassie Brabaw's Scientific American article, Why Feeling Close to the Finish Line Makes You Push Harder.

Katy Milkman also educated me about the fresh start effect.

*The goal-gradient effect is also known as the goal-gradient hypothesis

The goal-gradient effect

This is surely at least part of the reason that “software is eating the world.”

But I’m sure coffee will stick around for a bit too.

Rival and non-rival goods

Crossmodal perception is when senses interact in sometimes surprising ways. Some fun examples:

Coffee tastes better when you don’t have a loud coffee machine near you, and it also tastes more intense and less sweet if the mug is white.

In the atmosphere of a pressurised cabin when flying, with decreased humidity and air pressure and significant background noise, things taste less sweet or salty.

If you can’t hear the crunch of, say, a Pringles potato chip, then it tastes less fresh.

You might enjoy Nicola Twilley’s super New Yorker article, The Illusion of Taste, which has more of the science and plenty more examples.

Crossmodal perception

A word from the Sami people of Northern Norway, Finland or Sweden, from ‘coffee’ and ‘boil’, used as a measure of distance for how far you can go before you need a cup of coffee.

Kaffikok

The half-life of caffeine is about 4 hours.

The data vary, but for a medium-sized adult, you can probably expect half of the caffeine from that 3 pm cup of coffee to still be doing half of its thing about 7 pm, 4 hours later. Apparently, smokers deal with caffeine quicker, and caffeine sticks around in children much longer.

You can expect about 10 minutes before it first kicks in, which, I suppose, is why if you’re feeling tired while driving, it’s a decent plan to take a break and drink a coffee, then have a 15-minute nap. See tiredness can kill, take a break. Once it starts to kick in, you might hit peak caffeine any time from 45 minutes to 2 hours later.

Caveat: The chart visualisation is extrapolated from reported data, so the shape is only approximate.

Some references say longer, and some say from 3-9 hours or so. My source, which seemed pretty comprehensive, was:

Bertil B. Fredholm, Karl Bättig, Janet Holmén, Astrid Nehlig and Edwin E. Zvartau, Actions of Caffeine in the Brain with Special Reference to Factors That Contribute to Its Widespread Use, Pharmacological Reviews March 1999, 51 (1) 83-133;

The half-life of caffeine

What's the difference between an americano and a long black coffee? I'd often wondered. Both seemed to be espresso and water.

Not everyone will give you the same answer in a coffee shop if you ask them. But my understanding is the difference between an americano and a long black comes down to the order of adding your water to your espresso — an americano — or adding your espresso to your water — a long black one.

If you’re making your own americanos or long black at home, you may notice that a long black seems to make a more satisfyingly luxurious-looking coffee as it does a better job of preserving the crema on top.

Espresso, filter, americano and the redeye.

Perhaps I should speak to someone about this.

An americano and a long black: the difference

A microlife is thirty minutes of your life expectancy. You can use it up by chilling for 30 minutes or you could start to speed through them by smoking a few cigarettes or having a few drinks.

A simple way to bring difficult-to-grasp long-term, slow-burn risks into a unit that can motivate you and a handy way to compare risks.

Even better, you gain a microlife with 2-3 cups of coffee. Win!

Interesting? See Microlives: A lesson in risk taking, by Cambridge University Professor of risk David Spiegelhalter. Or see his 15 min TED talk: Motorbikes, Terrorism, Heart Attacks, Sausages: Professor David Spiegelhalter at TEDxOxbridge, or the full paper.

Microlife: The unit of life

How to make Irish coffee

Espresso: steam forced through coffee grounds

Filter coffee: water dripped through coffee grounds and a filter

Redeye coffee: espresso topped up with filter coffee

Clear the fog with a redeye

My technique, for when you really have to get somewhere and are starting to feel tired: Pull over, neck coffee, 15 min shut-eye, cruise on. I have read that this is called a nappuccino.

There’s some science behind this: the half-life of caffeine.

Tiredness can kill. Take a break

I regularly make half-caf coffee. I think there’s a gap in the market. Why is coffee so binary?

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Category: coffee