The science of persuasion

Here, we look at the science of persuasion and set out seven methods scientifically proven to heighten influence and boost your chances of success when conducting negotiations.

All jobs call for a level of persuasiveness and the role of in-house lawyer is no exception.

Whether you’re seeking additional resource from the FD, trying to convince a business unit head that your risk management strategy is the best option or attempting to recruit a leading expert into your team, it pays to be persuasive.

Persuasion – art or science?

The top company sales person, the super-negotiator, the politician with the common touch. All these people are successful because they’re persuasive. They appear to have almost magical abilities to change other people’s behaviour or ways of thinking. They are the artisans in the practice of influence.

However, you don’t have to be a natural to improve your powers of persuasion. Research shows that there are proven principles that, when used skilfully, can bring science into the equation and make you more influential.

When we make a decision or approve an action, we like to think we’ve considered all the available information and made an informed choice. However, in an increasingly busy world, cognitive overload often leads us to take shortcuts in the form of predictable, fixed-action patterns to make decisions. By studying these mental heuristics, researchers have shown that we can narrow the many hundreds of influencing tactics down to seven universal techniques for influencing others.

So, whether you’re selling to a client, making the case for extra resource or simply asking a neighbour to trim their hedge, develop your technique in these core areas.

1. Reciprocate

If someone invites you to their party, you typically feel duty-bound to return the kindness and invite them to a future party you throw. Similarly, if a colleague assists you on a project at work, you’ll probably be willing to assist them with something they’re working on.

Put simply, people feel obliged to give back to others the form of behaviour, gift or service they have received first. In the context of a social obligation, people are more likely to say yes to someone they feel they owe.

The keys to the principle of reciprocation are to:

  • Be the first to give; and
  • Make the act of giving personalised and unexpected.

2. Make it scarce

People will queue for hours, and even days, to obtain an exclusive product. Email marketers bombard us with limited-time sale offers for their products. In short, if something’s in short supply, people’s desire for it increases.

The science tells us that to persuade others to take up your offer, it’s not enough to just explain the benefits. You must also highlight what’s unique in your offer and what they stand to lose by turning it down.

People view opportunities as more valuable if they believe them to be scarce, rare or dwindling in availability.

3. Get authority on your side

Whether choosing a film to watch or a business to invest in, people seek out the opinions of leading commentators and experts before making their choice. Buyers, both professional and retail, often consult product reviews before making purchasing decisions.

People are assured, and therefore influenced, by what those they perceive to be credible, knowledgeable experts say.

So, to persuade others, have a respected third party in your field testify to your credibility. This works even if that third party is connected to you or is likely to gain from your success.

4. Be consistent

Once they take up a position in a debate, most people are reluctant to change their minds. We have a tendency to look exclusively for evidence that confirms our prior assumptions. This is known as confirmation bias.

We can activate this principle of consistency by triggering small, initial commitments from those who we’re trying to persuade. To be most effective, these commitments should be perceived to be voluntary, proactive and, ideally, openly made so as to be firmly established and hard to backslide from. Then, a case that reinforces a person’s stated stance becomes more compelling.

5. Be liked

We have an inbuilt preference to say yes to people we like. In this context, like means:

  • These people are similar to us;
  • They’re people who pay us compliments; and
  • They cooperate with us to achieve mutual goals.

We respond favourably to people who meet these criteria. The minimum threshold for each varies by individual, however, persuasive people are quick to understand where the balance lies.

For example, when in a negotiation, sharing some personal information and establishing something you have in common can double the chances of an agreeable outcome for both parties.

6. Find the consensus

The vast majority of people who shop on Amazon rely on ratings from other buyers.

And recent statistics suggest that more than two-thirds of content viewed on Netflix is chosen based on what other subscribers are watching.

This tells us that people will look to the actions and behaviours of others to determine their own choices, especially when they’re split between two or more options. So, we can persuade people by pointing to what many others are doing.

However, to make this notion of social proof work, we need to pick a proximal peer. This is someone the person you’re trying to influence feels close or related to. For this reason, your proximal peer shouldn’t be an aspirational individual such as a celebrity.

7. Be a chameleon

Why do some waiters get 70% higher tips than their colleagues in the same restaurant and why are some speed-daters three times more likely to go on a second date?

By being a chameleon. Subtly imitating or mirroring the mannerisms of the person you’re trying to influence can deepen social bonds and turn strangers into allies. Small acts like crossing your legs, tilting your head to the same side or even gesturing with the same hand can help you persuade others.

Scientific studies show that negotiators who subtly alter their behaviour, language and mannerisms through the chameleon technique can be five times more effective in reaching a favourable agreement.


Influence: The Psychology of Persuasion by Robert Cialdini.


Some people are natural influencers, whereas others have to work on their powers of persuasion. The good news is that there are techniques that we can develop to make us more influential. Science has proved that the principles of reciprocity, scarcity, authority, consistency, likeability, consensus and mirroring can make the difference between a successful and unsuccessful negotiation.