It’s not difficult to persuade anyone of the prevalence and significance of the number three in Western culture. It’s everywhere, from sport (three points for a win, hat-tricks), fairy tales (Bears, Pigs, wishes), literature (Musketeers), films (Amigos, Stooges), to religion (the Trinity), interior designers (three ornaments on a shelf) even stand-up comedy (the rule of three elements in a joke). We even say that bad new comes in threes! There is something intrinsically satisfying about the number three to our pattern-seeking brains.
In psychology there are also plenty of triads such as Sigmund Freud‘s id, ego and superego (in psychoanalysis) and Eric Berne‘s parent, adult, child (in transactional analysis). I was surprised at just how many there are, so much so, that when writing my book Unlock Your Confidence I found it useful to use a triangle device to communicate the essence of psychological theories, without getting too bogged down in the details. I tested in workshops and it was a fast and effective way of introducing new material without taking away from the hands-on, experiential nature of the workshops. People really seem to get ‘three’.
It turns out that the rule of three offers a blueprint for persuasiveness. Kurt Carlson (Georgetown University) and Suzanne Shu (University of California) in their research paper ‘When Three Charms but Four Alarms’, find the ideal number of claims to include in a persuasive argument. People, firms and products should all use the ‘charm of three’ when making positive claims. Two is not convincing and adding a fourth point is viewed as a step too far. It actually has a detrimental effect and increases scepticism..
This post is deliberately brief as the rule of three has endless applications. I figure your time would be better spent updating your CV (resume), updating your websites, rethinking your presentations, sales pitches, marketing and advertising campaigns or just the humble negotiations in relationships. There is no need to come up with as many convincing reasons as long as your arm. Three will do nicely.