If you want to get better at persuading and influencing people, science is here to help.

Based on research by Dr. Robert Cialdini, a leading social psychologist, it turns out that because of the sheer magnitude of information you have to take in every day, your brain has developed 6 shortcuts to help you make decisions. If you know what they are and how to tap into them, you can greatly increase your ability to persuade.

As a self-described science geek, this research has had me hooked for years. Then I took it to a practical level and applied it in real business situations. This science stuff works.

Here are the basics:

1. "I like you" matters

The research doesn't tell you to try to be everyone's best friend.

What is important is common ground. Simply put, if I feel like I have something in common with you, I am more likely to be influenced by you.

The next time you are trying to persuade someone, take a step back to create common ground. Cialdini's research showed one case where just doing this increased successful deal closing by 35%.

2. You want to reciprocate

Do you return favors? It turns out that you do, even if you don't consciously think about it. One study showed that the simple act of a waiter bringing a mint increased tip amounts by about 3%. If the waiter brought two mints, tips actually increased by 14%.

I recently took my son to Baskin-Robbins. As we were paying, the cashier took out a $1 off gift card for me and happily swiped the card.

I reached into my pocket, took out my wallet, and put $2 in the tip jar. I knew the research but couldn't help myself. I smiled as I walked out thinking, "She's good."

One of the keys to reciprocation as shown in Cialdini's research is to be the first to give, which is interesting when you compare it to what many of you have been taught about negotiation where it is common to say that he who speaks first loses.

3. You want to honor your commitments

Have you ever wondered why your dentist has you fill out your next appointment card instead of filling it out for you?

It turns out that you want to follow commitments in writing, and when you write it yourself, your commitment increases significantly.

The research also shows that it is easier for you to make big commitments after you have made smaller commitments on the same topic.

This is particularly relevant when trying to secure funding. As much as you might want to ask for a large amount upfront, the research suggests that you should start small and establish a commitment precedent for continually bigger amounts.

4. You defer to authority

When my dad was young, he was a veritable car expert. He and his friends took their cars apart, re-worked them, put them back together, and raced them. Naturally, he worked at a full service gas station (anyone remember those?).

A customer drove in one day, and my dad said to his co-worker:

"I'll be you I can convince that guy to let me take the air out of his tires."

His co-worker took the bet. My dad walked up to the car and said:

"I noticed that you have old air in your tires. That's a problem. We need to take out the old air and put new air in."

Amazingly, the driver let him do it and probably drove off really feeling the difference. Why? As my dad tells the story, because he had a gas station uniform on and came out of the garage with greasy hands after working on a car. He therefore was an authority on cars.

As much as this example shows misguided behavior (my dad won't be offended), the research supports the notion that people are influenced by others they believe are authorities.

So even if you have no formal role authority, find a way to show subject matter authority.

5. Consensus is powerful

Will someone be more influenced by you if you show them that other people just like them have done what you are asking them to do? The research gives us a resounding "yes" even if they don't know the other people at all.

This is why good benchmarking is so powerful. And if you can personalize the benchmark, the level of influence goes up exponentially.

6. The surprising thing about scarcity

In simple terms, the scarcer something is, the higher the value we place on it. The higher value we place on something, the easier it is to persuade someone to do that very thing.

Here is a great video from Robert Cialdini which distills this down into 10 minutes of entertaining practical knowledge. Try these out. You will find that at the very least they will change your strategies the next time you are looking to influence someone.