WHY do people say "yes"? How can we get them to comply with our requests?

Dr David Palmer, an expert on organisational development and marketing, says: "People are frequently willing to say 'yes' automatically without thinking first. It makes their lives simpler and smoother.

"But what most of us (who want to influence others) are trying to overcome is the opposite phenomenon, when they've programmed themselves to say 'no' without thinking about it."

Here is where the emotional triggers come in. Researcher Robert Cialdini at Arizona State University describes the Six Weapons Of Influence in his book, Influence, Science And Practice.

1. Reciprocation

All of us are taught to find some way to repay others for what they do for us. This is an extremely powerful tactic.

In one experiment, for example, half the people attending an art appreciation session were offered a soft drink. Afterwards, all were asked if they would buy 25-cent raffle tickets.

Guess what? The people who had been offered the soft drinks purchased twice as many raffle tickets, whether or not they had accepted the drinks.

You can build a sense of indebtedness in someone by delivering a number of uninvited "first favours" over time. They don't have to be tangible gifts. In today's world, useful information is one of the most valuable favours you can deliver.

2. Commitment and consistency

Once people have made a choice or taken a stand, they are under both internal and external pressure to behave consistently with that commitment.

When you can get someone to commit verbally to an action, the chances that they'll actually do it go up sharply. For example, before starting your next meeting, ask each person to commit to following the posted agenda.

Then, if anyone goes off on a tangent, just ask them to explain how it fits the agenda. If they can't, they will quickly fall back in line.

3. Social proof

People decide what is correct by noticing what others think is correct. This principle applies especially to the way people determine what constitutes correct behaviour.

For example, one of the important, and largely unconscious, ways you decide what is acceptable behaviour on your current job is by watching the people around you, especially the senior managers or old -timers.

This principle of influence kicks in even more strongly when the situation is uncertain or people aren't sure what to do.

Product endorsements are the most obvious application of social proof. If you want someone to buy something, show him that others like him believe in your product or are using it.

4. Liking

People love to say "yes" to requests from people they know and like. And people tend to like others who appear to have similar opinions, personality traits, backgrounds or lifestyles.

Most people are also suckers for flattery, even when they know it isn't true. When you have a good opinion of yourself, you accept praise and like those who provide it. All salesmen worth their salt have mastered this tactic.

People also tend to like and trust anything or anyone familiar. The best way to build this familiarity is to have frequent and pleasant contact with those you want to influence.

5. Authority

Most of us are raised with a respect for authority, both real and implied. Some people are more strongly influenced by authority than others, and compliance can vary according to the situation.

For example, it's 11pm, and the doorbell rings. Two men in police uniforms want to come in and ask you a few questions. Most people respect such authority and would comply.

But if it were 3am and the men were in plain clothes and claimed to be detectives, most will hesitate to comply. The men would have to overcome resistance with more proof of their authority, like badges or a search warrant.

You can put this general principle to use by citing authoritative sources to support your ideas. Dress like the people who are already in the positions of authority that you seek. Be sure others know that your education and experience support your ideas.

6. Scarcity

Nearly everyone is vulnerable to some form of the principle of scarcity. Opportunities seem more valuable when they are less available. Hard-to-get things are perceived as better than easy-to-get things.

For example, the object you have almost decided to buy is out of stock. The salesman offers to check their other stores, and the store across town has one left. Do you buy it? Of course!

Whenever appropriate, you can use the scarcity principle to influence others. The possibility of losing something is a more powerful motivator than gaining something. Let others (a customer or your boss) know what they will lose if they refuse to your offer.

The Six Weapons Of Influence are incredibly powerful and can be combined in many ways. Use them whenever you approach people you want to influence.