Weekday Wisdom: Burgers, Bikinis and Black Friday 💰

Now let’s talk about Social Proof.

It’s the fancy behavioural science term for "Monkey see, monkey do."

Evolutionarily, this saved our skins. If you saw the rest of your tribe running screaming in one direction, it was usually a good idea to follow them without asking why.

Today, we rarely run from predators, but our brains haven’t recalibrated. We still look to others to decide what is safe, what is cool, and what is worth buying.

Here are 10 real-world examples of how the crowd hacks your brain:

1. The Madoff Method

Fraudsters like Bernie Madoff were masters of social proof. He famously told clients he managed money for celebrities (which he did) to dupe ordinary people into his Ponzi scheme. If the "smart money" is doing it, surely it’s safe? (Spoiler: It wasn't).

2. Red Bull’s Trash

When Red Bull launched, they filled bins in high-traffic areas with empty, crushed cans. It gave the illusion that everyone was drinking it, turning their trash into a powerful marketing asset.

3. Apple’s White Headphones

When the iPod launched, headphones were universally black. Apple made theirs white. It was a high-visibility signal that the wearer had the "new cool thing," creating a walking billboard that triggered envy and imitation.

4. Kendall Jenner’s Bikini

The Aussie brand Triangl couldn’t afford to pay Kendall Jenner. So, they sent free bikinis to all her best friends instead. Kendall saw her inner circle wearing them, got FOMO, and messaged the brand asking for a pair. She posted it for free, and the brand exploded.

5. McDonald’s Signage

Over 99 Billion Served." This famous tagline is a subtle way of saying, "There is no way 99 billion people are wrong about these burgers."

6. Jo Malone Store Opening

When launching her scent empire, Jo Malone asked friends to walk around wealthy London neighbourhoods carrying her branded boutique-looking bags. The bags were often empty, but the perception of exclusivity was full.

7. Nightclub Queues

Bouncers often hold people back when the club is half-empty to create a queue outside. A long line signals popularity. If people are waiting, it must be good.

8. Canned Laughter

Sitcoms use laugh tracks for a reason. Hearing others laugh, even artificially, triggers a primal response that makes us more likely to chuckle along.

9. Netflix’s ‘Top 10’ Row

Netflix uses titles such as ‘Top 10 TV Shows in the UK Today, ’ which is pure descriptive social proof. It sends the signal that ‘everyone else is watching this right now.’

10. Shopping Trolleys

When Sylvan Goldman invented the shopping trolley, customers refused to use them. Men felt they were weak, women felt they looked like baby carriages. Goldman hired actors to push them around his store. Once shoppers saw "others" doing it, the trolley became the global standard.

Big love,

Chris & the 42courses team x

p.s. If you love smart ideas and Behavioural Science, have a look at our latest course with the incredible Dan Ariely, or, of course, the ones from Richard Shotton, or Rory Sutherland, it’s a much more mentally stimulating black friday spend + they might just save you from yourself :) (Use the code BLACKFRIDAY25)

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