We feel validated by doing what others are doing.

What is social proof?

‘Social proof’ was first used by Robert Cialdini in his 1984 book. It describes the way our behaviour is influenced by what others are doing.

We tend to ‘follow the herd’. So, if a lot of our peers favour an action we’re more likely to follow suit, similarly if a lot of people don’t like something we’ll steer clear of it.

The evidence it works

Psychology is inundated with experiments that prove this bias, but here’s one of the funniest we’ve come across:

Where it fits in our behavioural model – The ‘means’ METRIC

The three core principles of our Behavioural Model is that every behaviour has to have a motivation, trigger and the means.

The means are the resources to get what you want. This isn’t just money – choosing and buying also costs time and effort, thought and worry.

In theory, the means depend on what’s in short supply. So if we’re short of time, we’ll spend money. If we don’t want to take a risk, we’ll invest more thought. If everyone else is doing one thing, we’d rather join the queue and spend time, than feel like the odd one out.

But our judgement of these things is often flawed. For example, we can only judge numbers in comparison with other numbers and we’re inclined to not waste energy, so the easier something seems the more likely we are to choose it (like joining the queue). Which forms the basis of our Behavioural Model.

The means model is split into six different sections: Money, Effort, Time, Risk, Individuality, and Conscious thought. Which handily spells METRIC.

Social proof falls under individuality, or the herd impulse, meaning we judge something based on what our peers do.

How we've used it with clients


By including “4,127 five star Trustpilot reviews” with examples on the website we show how valued our service is. Which, in turn, provides social proof helping to build trust and encourage more sales.



In Bulb’s latest ads they have a number of lines that use social proof, from ‘fastest growing’ to ‘biggest green company’ to ‘really recommended’.


We’ve all come across an influencer ad on social media. They’re a classic case of social proof, especially when you team it with a plethora of likes and comments too.

How we can help you

We’re an agency that makes your marketing more efficient with behavioural science. To find out how we can help you reach your goals, get in touch now.

By Ellen Jackson

Creative Copywriter