The Words That Most Sell and Convince
Introduction
For years an idea has circulated, repeated like dogma, that only 7% of communication is verbal. It's worth being skeptical of anyone who states it flatly: it comes from experiments in the late sixties (Albert Mehrabian's studies, 1967 and 1971) whose conclusions were not generalizable to everyday conversation, something the scientific community itself has long acknowledged. Whatever the exact weight of words, it's certainly been shown that they influence behavior — a great deal. These are five of the most powerful for persuading, and why they work.
1. "Because"
Probably the most potent. In a famous experiment described by psychologist Robert Cialdini, a person asked to cut in line at a photocopier in three different ways:
- "Can I use the copier?" → they were let through 60% of the time.
- "Can I use the copier, because I'm in a hurry?" → 94%.
- "Can I use the copier, because I have to make some copies?" → 93%.
The astonishing part is the third version: it provides no real reason at all (of course you use a copier to make copies!), and yet it works almost as well as the second. The conclusion: very often, on hearing the word because, the brain assumes a reason exists and doesn't examine its logic.
How to apply it: always accompany your requests with an explicit "because", with a real reason behind it.
2. "Free to"
More than a word, it's a concept: if your listener feels you respect their freedom to choose, they're more likely to end up doing what you propose. People dislike being constrained, and we rebel against whoever tries; that's why it's so hard to convince a stubborn person with arguments: they feel you're trying to take away their position.
In the largest experiment on persuasion ever conducted — a meta-analysis with more than 22,000 participants by Christopher Carpenter (2013) on the "But You Are Free" technique — it was found that adding the phrase "but you're free to decide" at the end of a request doubles the chances of it being accepted. The reason: the person feels the decision is theirs and that you aren't pressuring them.
How to apply it: after giving your recommendation, remind the other person that the final decision is freely theirs.
3. Someone's name (and "you")
A myth circulates about a Yale study according to which "you" is the most persuasive word; in reality that study never existed. What is documented is that hearing or reading your own name activates brain regions associated with pleasure, which increases the credibility we give to messages containing it.
How to apply it: learn your conversation partner's name as soon as possible and use it without overdoing it. In written communication (emails, messages), personalizing with the name has a similar effect.
4. "Free"
In a well-known study by behavioral economist Dan Ariely (collected in Predictably Irrational), participants chose between a premium-brand chocolate at 15 cents (its average real price) and an ordinary one at 1 cent: 73% preferred the premium one, which was a bargain. But when both dropped by one cent — the premium to 14 and the ordinary one to free — 69% went for the free one, even though the relative price difference was exactly the same. The word "free" exerts an irrational pull.
How to apply it: when you offer something at no cost, don't take it as understood: expressly mention that it's free.
5. "New"
Neuroscience studies indicate that the word new activates the brain's reward center, because over the course of evolution curiosity and the search for novelty favored survival. That's why a long-standing product, presented with an eye-catching "new flavor", tempts us into making an exception.
How to apply it: if something is new — or can legitimately seem so — highlight that novelty in your message.
A warning about persuasion
These words are tools of influence, not manipulation. They work best when they accompany an honest proposal and a real reason; used to deceive, they erode trust the moment the trick is discovered. Ethical persuasion consists of making it easier for the other person to say yes to something that suits them, always respecting their freedom to say no.
Conclusion
Words influence behavior far more than certain popular myths suggest. "Because", "free to", someone's name, "free" and "new" are five of the most effective, each anchored in a different psychological mechanism: the need for reasons, the desire for autonomy, the pleasure of hearing our own name, the pull of the free and the fascination with the new. Use them with judgment and honesty, and you'll see their power.
References
- Langer, E., Blank, A., & Chanowitz, B. (1978). The mindlessness of ostensibly thoughtful action: The role of "placebic" information. Journal of Personality and Social Psychology, 36(6).
- Carpenter, C. J. (2013). A meta-analysis of the effectiveness of the "But You Are Free" compliance-gaining technique. Communication Studies, 64(1).
- Ariely, D. (2008). Predictably Irrational. HarperCollins.
- Cialdini, R. B. (1984). Influence: The Psychology of Persuasion. Harper Business.