Negative Social Proof

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In the early 2000s, communications professor Bob Hornik¹ wanted to see if anti-drug ads worked.

He gathered data on thousands of teenagers. He tracked their exposure to anti-drug ads and their marijuana use over time.

The results?

The ads didn’t reduce drug use. They increased it.

Teenagers who saw the ads were more likely to smoke marijuana.

Why?

Because the ads unintentionally reinforced the idea that drug use was common.

This is called negative social proof.

People look to others to determine what’s normal. The more they hear about something, the more they assume it’s widespread.

Anti-drug campaigns meant to deter use were doing the opposite. They showed that drug use was a big enough problem to require national ads.

Negative social proof examples

1️⃣ To change behaviour, highlight what people should do.

Don't highlight that negative behaviour is commonplace.

At Arizona’s Petrified Forest², a sign warning that many stole wood backfired.

Rather than reducing theft, the sign doubled the amount of theft.

A new sign urging preservation was more effective, reducing theft.

2️⃣ The UK's largest retail bank made the same mistake.

To encourage saving, they advertised how "11.5 million Brits have less than £100 saved".

As we know, that will only encourage negative behaviour.

3️⃣ In the UK, the NHS faces a recurring issue: missed medical appointments.

To tackle this, some managers displayed stats on no-shows.

But research³ found this backfires. Seeing high numbers normalised behaviour.

A simple shift solved it. New signs emphasized that most patients arrive on time. No-shows dropped significantly.

Thanks to Jonah Berger's book⁴ for this week's newsletter inspiration.

And a big thanks to today's sponsors!

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Cheers Phill!

P.S. At the time of writing, just six spots are left on the Nudge Unit. ​

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