People prefer faces. In our evolutionary path, as human beings we’ve become better and better at recognising faces, not least because of survival reasons. Our ancestors would survive only if they were good at recognising the faces of hidden predators.
That’s one of the reasons why faces attract so much attention today. There is even a part of our brain which is dedicated to the recognition of faces and so it’s no surprise if mass communication heavily relies on images with faces. A face that looks at us has a preferential channel for our brain. Marketing professionals say that if you want to sell you have to use faces in your marketing material. Faces have become synonymous with reliability ("If I say so, you can trust me").
Using images of faces can be an effective way to capture the viewer’s attention—and this holds true in different communication media: posters, newspapers, billboards, social media and also in presentations.
But you have to be careful. Precisely because faces capture attention, you should consider where the audience's gaze will go when looking at your slides. For example, when we combine images of people and text, if the person looks to the left of the slide and the text is placed on the right, the risk is that the audience will follow the person's gaze and lose the message.
A better alternative is to ensure that the gaze follows the text. See where the lady’s gaze goes in the sample slide below? I didn’t place the text in that position at random. When you show such a slide, the audience will first look at the image (faces capture attention), then they will follow the woman’s gaze pointing at the text which is the message you want to convey. When you pay attention to these details, you’re putting yourself in your audience’s shoes in order to guide them through the various elements that make up a slide.
Riccardo Falcinelli—visual communication expert and author—explains in one of his books that the face recognition mechanism also exists in animals. For example, the sheep brain is activated when sheeps see the face of other sheeps. Also, there’s a type of fish that recognises its partner simply by a red spot on the belly. Why is this useful to know? Because the human brain—although very complex—has evolved from simple structures such as those of animals. A single human neuron is not in itself different in its functioning from a single animal neuron—the difference is that we have a huge number of neurons and that’s what creates the complexity of the human brain.
Now the question is, should we use images of faces in our presentations? It depends, there’s no unique answer. My only recommendation is that if you do use them, remember that faces capture attention and therefore you should look at the arrangement of facial images and text. Make sure the gaze goes towards the text so that the audience’s gaze is guided towards the message you want to communicate. It's a small detail, but it all adds up.
If you want to learn more about how to make better presentations, download my report Top 7 Mistakes People Make When Creating Business Presentations.