What people really mean when they say “Beautiful slides!”

Beautiful slides

People’s perception of truth plays a critical role in how seriously they will consider your message and ultimately, in the decision they’ll make about your idea, product or company. What do we know about truth and can we anticipate how the audience will perceive our presentation? It turns out the answer to that question is linked to the concept of beauty.

Beauty is truth

My work always tried to unite the true with the beautiful; but when I had to choose one or the other, I usually chose the beautiful”.
Hermann Weyl
mathematician and philosopher (1885 –1955)

Beauty and truth have long been considered two sides of the same coin. The ancient Greeks had a term for that, Kalos kagathos, the critical balance of the beautiful (kalos) and the good (agathos). In medieval art, it was considered inconceivable that something untruthful could be beautiful. The human propensity for liking and accepting what is perceived as beautiful and elegant is not limited to the arts. On Einstein’s theory of relativity, Nobel prize-winning physicist Paul Dirac wrote: “One has great confidence in the theory rising from its great beauty” (1).

Easy on the eyes
It turns out that there is an underlying mechanism at play when people evaluate both beauty and truth. Psychologists call it “processing fluency” and it describes the ease, or difficulty, of completing a mental task, for example: understanding the strategy on a slide.

Studies have shown that the more fluently/easily we process information, the more positive is our aesthetic response. For example, pictures preceded by matching words (e.g. a dog and the word dog) are liked significantly more than pictures preceded by merely related words (e.g. a lock and the word key), which, in turn, are liked significantly more than pictures preceded by unrelated words (e.g. a desk and the word snow). This result is also consistent with people’s preference for symmetric shapes and average faces, which are easier to process (2, 3).


Additionally, information that requires lower processing effort is also more likely to be accepted as true, as opposed to information presented in a less accessible form (4). Thus, a statement clearly printed in dark text against a white background (e.g. “Bolligen is in Peru”) is more likely to be accepted as true than a statement printed in light text against a light background (e.g. “Osorno is in Chile”. Guess which statement contains correct information?


Interestingly, the decision to like and trust is almost instantaneous. A study by Google revealed that people consistently rated simpler websites as more beautiful compared to more visually complex ones and that the decision about whether to stay on a website was taken within 1/50th to 1/20th of a second (5).

This cumulative evidence implies that any variable that facilitates information processing results in increased liking and is perceived as true.

Love your slides
How can we use this knowledge to our advantage during a presentation? We could use slides that are simple, clear and easy to process when we want to engage our audience, creating a flow and steering away from unnecessary and distracting discussions. This is useful, for instance, when introducing a project or launching a new strategy. If we want to trigger a discussion or questions on specific aspects of our story, we should make sure that those elements are presented in such a way as to slow down processing fluency, for instance by lowering readability or increasing information load.

It’s a fine balance here. Having only easy slides might make your audience too passive and lower your perceived value, as the information presented will feel commonplace and self-evident. On the other hand, an overkill of complex information that nobody can even read will have your public doubt your credibility and leave the presentation unconvinced and skeptical.


  1. McAllister (1999). Beauty and Revolution in Science. Cornell University Press.
  2. Schwarz, Song & Xu (2009). When thinking is difficult: Metacognitive experiences as information. In M. Wänke (Ed.) The social psychology of consumer behavior. New York: Psychology Press.
  3. Reber, Schwarz and Winkielman (2004). Processing Fluency and Aesthetic Pleasure: Is Beauty in the Perceiver’s Processing Experience? Personality and Social Psychology Review, 8 (4), 364-382.
  4. Reber and Schwarz (1999). Effects of Perceptual Fluency on Judgments of Truth. Consciousness and Cognition 8, 338–342.
  5. Tuch et al (2012). The role of visual complexity and prototypicality regarding first impression of websites: Working towards understanding aesthetic judgments. International Journal of HumanComputer Studies, 70 (11), 794-811.

Image: The Birth of Venus, Botticelli (1445-1510).