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How many animals of each species did Moses take on the Ark?

If you answered "two," then please reread the question.

It was, of course, not Moses but Noah who led the animals into the Ark. But don’t feel too bad if you fell into the trap. Most people do.

When this question—known as the Moses Illusion(1)—was put to students in the 1980s, eight out of 10 failed to spot the trick.

Surprisingly, the likelihood of a reader being caught depends, to some extent, on the font. When a less familiar typeface is employed—in one study Brush Script was used—those taken in fell from eight out of 10 to just over half (53 percent).

In my latest book, The Brain Sell: When Science Meets Shopping, I describe several ways in which advertisers, retailers, and marketers use fonts to create a particular impression in a consumer’s mind and prime them to respond in a positive way to a sales message.

In our lab we have used brain imaging and eye-training to measure precisely the effect of typeface choice both in stores and online.

Here are a couple examples of recent studies which further illustrate this point:

An Elegant Font Makes Soup Taste Better

In a study conducted by my lab, two groups of participants were asked to rate a tomato soup for taste, freshness, and enjoyment. Before being given the soup, each participant read one of two menus. While both menus described the dish as "rich and creamy," one was printed in rather unexciting Courier and the other in elegant Lucida Calligraphy. Although everyone consumed soup from the same tin, two-thirds more of those given the Lucida Calligraphy menu rated it as tastier, fresher, and more enjoyable than those in the Courier group.

Familiar Fonts Increase Trust in Products

In a study conducted by Nathan Novemsky, associate professor of marketing at the Yale School of Management, and his colleagues, two groups read a leaflet detailing information on cordless telephones. One was printed in a familiar font; the other in an unfamiliar one. The participants were then asked whether they would like to buy a phone right away or think about it. Four out of 10 in the unfamiliar font group said they wanted time to think about the purchase, while only 17 percent in the familiar font group did so.

“People associate familiarity with truth, and high fluency can lead to an inference that a statement is familiar,” Novemsky explains. “The more easily a given target can be processed, the more positively it is evaluated.”(2)

Why KISS Doesn't Always Work

Does the well-known KISS mantra—Keep It Simple and Straightforward—always hold true? When creating sales messages, the answer is probably ‘yes.’ But with other types of printed information, this not necessarily the case: When English, physics, and chemistry students attending a high school in Ohio studied from texts in an unfamiliar font, they achieved higher marks on their exams than those given books in a familiar typeface.

Researchers have also found that mental puzzles are solved more accurately, and product reviews read more closely, when the font chosen requires greater attention to be paid.

Two Ways of Thinking

Why should font choice make such a difference?

The answer lies in the way we think.

Most of the challenges that face us each day can be dealt with perfectly effectively through a form of thinking that operates, much of the time, outside conscious awareness. While this allows us to do much of our routine on "autopilot," the system is—as the Moses Illusion demonstrates—prone to error.

“During any given second, we consciously process only 16 of the 11 million bits of information our senses pass to our brains," explains neuroscientist Tor Norretranders. “The conscious part of us receives much less information than the unconscious part.”(3)

When a task is perceived as unfamiliar, unusual, or especially difficult we are obliged to invest greater time and attention to tackling it. We reflect, we analyze and apply reason and logic. Such thought processes are relatively slow, can only handle limited amounts of information at any one time, and consume a great deal of energy.

“The often-used phrase 'pay attention' is apt,” says Nobel Prize–winner Daniel Kahneman. “You dispose of a limited budget of attention that you can allocate to activities, and if you try to go beyond your budget, you will fail.”(4)

A familiar font enables the eyes to skim effortlessly across a text, often without much attention being paid. An unfamiliar font, by contrast, slows us down and so increases our chances of spotting anomalies—like the substitution of Moses for Noah.

By moving away from the easy-to-read fonts in the traditional textbooks, teachers in the Ohio study encouraged students to pay closer attention—and think more deeply about—what they were reading.

When it comes to our finding that font choice can affect the taste of soup, it seems likely that the elegant typeface subconsciously primed diners to perceive food as superior and therefore tastier and more enjoyable.

So there are occasions in which information presented in an unfamiliar and more mentally-challenging font will be more effective. By obliging readers to pay greater attention and reflect more deeply on the text, their comprehension is likely to be improved and the accuracy of their recall enhanced.


(1) Erickson, T.A. & Mattson, M.E. (1981) From words to meaning: A semantic illusion. Journal of Verbal Learning and Verbal Behaviour, 20, 540 – 552.

(2) Novemsky, N., Dhar, R., Schwarz, N. & Simonson, I. (2007) Preference Fluency in Choice, Journal of Marketing Research, XLIV, pp 347-356.

(3) Kahneman, D. (2011) Thinking, Fast and Slow New York: Farrar, Straus & Giroux, p 23.

(4) Norretranders, T., (1998) The User Illusion, New York: Penguin Putnam Inc. 

The Brain Sell

When science meets shopping
David Lewis, Ph.D.

David Lewis, Ph.D., is a neuroscientist and Director of Research at Mindlab International

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