Persuasion quiz

The persuasion entries in the glossary, in brief. Open any one for the interactive demo behind it.

Social proof

People look to what others do to decide what is right, especially when they are unsure. In an interface, that means showing real evidence that real people use, rate and trust the thing.

Scarcity

Scarcity creates pull by making something feel more valuable when it seems rare or about to run out - like 'only 2 left' or 'offer ends in 5:00'. It works because the sting of losing an option outweighs the pleasure of gaining one.

Anchoring

Anchoring is the way the first number you see sets the frame for every judgement after it. Show a high price first and the real one feels like a bargain - not because it changed, but because you now have something to measure it against.

Loss aversion

Loss aversion is the way losing something hurts more than gaining the same thing pleases - roughly twice as much. The maths is identical; the feeling is not, which is why "don't lose this" pulls harder than "get this".

Framing effect

The framing effect is how the same fact, described positively or negatively, lands differently - "90% fat-free" feels healthier than "10% fat" though they are the identical tub. We react to the spin as much as to the substance.

Reciprocity

Reciprocity is the pull to return a favour - give someone something first and they feel quietly obliged to give back. Lead with genuine value and a later ask lands softly; open with the ask and it reads as a demand.

Authority

Authority is our tendency to trust, and act on, advice that comes from a credible source - an expert, a credential, an official badge. The same claim lands harder when it arrives with a reason to believe the person making it.

Unity

Unity is the pull of shared identity - we're more readily persuaded by people we count as one of us. Not just "people like me do this" (that's social proof) but "we are the same kind of person", a family, a profession, a tribe.

Social proof vs authority

Two routes to "you can trust this". Social proof points sideways - lots of people like you chose this. Authority points up - an expert or credential vouches for it. The crowd versus the expert; both borrow credibility, from very different places.

Goal-gradient effect

The goal-gradient effect is the way motivation rises as you near a reward - you push harder close to the finish line than at the start. Show visible progress, and even a small head start makes the goal feel reachable, so people keep going.

Decoy effect

The decoy effect happens when adding a third, intentionally worse option shifts your choice between the other two. The decoy isn’t meant to be selected - it’s there to make one of its neighbours seem like the better deal.

Sunk cost fallacy

The sunk cost fallacy is letting money, time or effort you have already spent - and cannot get back - keep you committed to something that is no longer worth it. The only sound question is what the next step is worth; the fallacy answers a different one - what you would be "wasting" by stopping.

Commitment and consistency

People feel a strong pull to act in line with what they've already said or done. So a small, early commitment - a tick, a tiny first step, a stated preference - makes a larger, consistent request far easier to agree to later. It's the "foot in the door": the first small yes paves the way for the bigger one.

Liking

Liking is the simplest of Cialdini's principles: we say yes more readily to people and brands we like. Similarity, genuine compliments, cooperation toward a shared goal, familiarity and warmth all raise liking - and liking, in turn, lowers resistance to a request. We agree with those we feel good about.

Sunk cost fallacy vs loss aversion

Loss aversion is the tendency for losses to feel worse than equivalent gains feel good. The sunk cost fallacy is one error that this bias can lead you into: continuing with something just because quitting would mean acknowledging what you’ve already spent is gone. One is the bias; the other is the mistake it can cause.