Researchers have been studying the factors that influence us to say yes
to the request of others for over 60 years.
And there can be no doubt that there's a science to how we are persuaded.
And a lot of the science is surprising.
When making a decision
it'd be nice to think that people consider all the available information
in order to guide their thinking.
But the reality is very often different.
In the increasingly overloaded lives we lead, more than ever
we need shortcuts or rules of thumb to guide our decision-making.
My own research has identified just six of these shortcuts.
As universals that guide human behavior,
they are:
Reciprocity,
Scarcity,
Authority,
Consistency,
Liking,
and Consensus.
Understanding these shortcuts and employing them in an ethical manner,
can significantly increase the chances that someone will be persuaded by your request.
Let's take a closer look at each in turn.
So the first universal principle of influence is Reciprocity.
Simply put, people are obliged to give back to others the form of behavior,
gift, or service that they have received first.
If a friend invites you to their party,
there's an obligation for you to invite them to a future party you are hosting.
If a colleague does you a favor then you owe that colleague a favor.
And in the context of a social obligation
people are more likely to say yes to those that they owe.
One of the best demonstrations of the principle of reciprocation
comes from a series of studies conducted in restaurants.
So the last time you visit a restaurant,
there's a good chance that the waiter or waitress will have given you a gift.
Probably about the same time that they bring your bill.
A liqueur perhaps or a fortune cookie or perhaps a simple mint.
So here's the question.
Does the giving of a mint have any influence over how much tip you're going to leave them?
Most people will say no.
But that mint can make a surprising difference.
In the study, giving diners a single mint at the end of their meal,
typically increased tips by around 3%.
Interestingly if the gift is doubled and two mints are provided, tips don't double.
They quadruple, a 14% increase in tips.
But perhaps most interestingly of all, is the fact that if the waiter provides one mint,
starts to walk away from the table, but pauses, turns back
and says, "For you nice people, here's an extra mint," tips go through the roof.
A 23% increase influenced not by what was given, but how it was given.
So the key to using the principle of reciprocation is to be the first to give
and to ensure that what you give is personalized and unexpected.
The second universal principle of persuasion is Scarcity.
Simply put, people want more of those things they can have less of.
When British Airways announced in 2003
that they would no longer be operating the twice daily London-New York Concorde flight
because it had become uneconomical to run, sales the very next day took off.
Notice that nothing had changed about the Concorde itself.
It certainly didn't fly any faster, the service didn't suddenly get better, and the airfare didn't drop.
It had simply become a scarce resource.
And as a result, people wanted it more.
So when it comes to effectively persuading others using the scarcity principle, the science is clear.
It's not enough simply to tell people about the benefits they'll gain
if they choose your products and services.
You'll also need to point out what is unique about your proposition
and what they stand to lose
if they fail to consider your proposal.
Our third principle of influence is the principle of authority.
The idea that people follow the lead of credible knowledgeable experts.
Physiotherapists for example are able to persuade more of their patients
to comply with recommended exercise programs
if they display their medical diplomas on the walls of their consulting rooms.
People are more likely to give change for a parking meter to a complete stranger
if that requester wears a uniform rather than casual clothes.
What the science is telling us is that it is important to signal to others
what makes you a credible knowledgeable authority before you make your influence attempt.
Of course this can present problems.
You can hardly go around telling potential customers how brilliant you are.
But you can certainly arrange for someone to do it for you.
And surprisingly the science tells us that it doesn't seem to matter if the person who introduces you
is not only connected to you but also likely to prosper from the introduction themselves.
One group of real estate agents were able to increase both the number of property appraisals
and the number of subsequent contracts that they wrote
by arranging for reception staff who answered customer enquiries
to first mention their colleagues' credentials and expertise.
So, customers interested in letting a property were told "Lettings?
Let me connect you with Sandra who has over 15 years' experience letting properties in this area."
Customers who wanted more information about selling properties were told
"Speak to Peter, our head of sales. He has over 20 years' experience selling properties.
I'll put you through now."
The impact of this expert introduction led to a 20% rise in the number of appointments
and a 15% increase in the number of signed contracts.
Not bad for a small change in form from persuasion science
that was both ethical and costless to implement.
The next principle is Consistency.
People like to be consistent with the things they have previously said or done.
Consistency is activated by looking for and asking for small initial commitments that can be made.
In one famous set of studies researchers found rather unsurprisingly,
that very few people would be willing to erect an unsightly wooden board
on their front lawn to support a Drive Safely campaign in their neighborhood.
However in a similar neighborhood close by,
four times as many homeowners indicated that they would be willing to erect this unsightly billboard.
Why?
Because ten days previously, they had agreed to place a small postcard
in the front window of their home that signaled their support for a Drive Safely campaign.
That small card was the initial commitment that led to a 400% increase
in a much bigger but still consistent change.
So when seeking to influence using the consistency principle,
the detective of influence looks for voluntary, active and public commitments
and ideally gets those commitments in writing.
For example, one recent study reduced missed appointments at health centers by 18%
simply by asking the patients, rather than the staff
to write down appointment details on the future appointment card.
The fifth principle is the principle of Liking.
People prefer to say yes to those that they like.
But what causes one person to like another?
Persuasion science tells us that there are three important factors.
We like people who are similar to us,
we like people who pay us compliments
and we like people who cooperate with us towards mutual goals.
As more and more of the interactions that we are having take place online
it might be worth asking whether these factors can be employed effectively
in let's say online negotiations.
In a series of negotiation studies carried out between MBA students at two well-known business schools,
some groups were told, "Time is money. Get straight down to business."
In this group around 55% were able to come to an agreement.
A second group however, were told,
"Before you begin negotiating, exchange some personal information with each other.
Identify a similarity you share in common
then begin negotiating."
In this group 90% of them were able to come to successful and agreeable outcomes
that were typically worth 18% more to both parties.
So to harness this powerful principle of liking,
be sure to look for areas of similarity that you share with others
and genuine compliments you can give before you get down to business.
The final principle is Consensus.
Especially when they are uncertain,
people will look to the actions and behaviors of others to determine their own.
You may have noticed that hotels often place a small card in bathrooms
that attempt to persuade guests to reuse their towels and linen.
Most do this by drawing a guest's attention
to the benefits that reuse can have on environmental protection.
It turns out that this is a pretty effective strategy leading to around 35% compliance.
But could there be an even more effective way?
Well it turns out that about 75% of people who check into a hotel for four nights or longer
will reuse their towels at some point during their stay.
So what would happen if we took a lesson from the principle of consensus
and simply included that information on the cards
and said that 75% of our guests reuse their towels at some time during their stay.
So please do so as well.
It turns out that when we do this, towel reuse rises by 26%.
Now imagine the next time you stay in a hotel you saw one of these signs.
You picked it up and you read the following message:
Seventy-five percent of people who have stayed in this room
have reused their towel.
What would you think?
Well here's what you might think.
"I hope they're not the same towels."
And like most people you'd probably think that
this sign will have no influence on your behavior whatsoever.
But it turns out that changing just a few words on a sign
to honestly point out what comparable previous guests have done
was the single most effective message leading to a 33% increase in reuse.
So the science is telling us that rather than relying on our own ability to persuade others
we can point to what many others are already doing especially many similar others.
So there we have it.
Six scientifically validated principles of persuasion that provide for small practical,
often costless changes that can lead to big differences in your ability
to influence and persuade others in an entirely ethical way.
They are the secrets from the science of persuasion.