I'd like to start with a small imagination exercise.

Imagine you're sitting at this table, facing me right now.

Now, I'm going to ask you to push one of these cards towards me.

So please imagine yourself pushing one of these cards towards me.

OK, so take the number matching the card you pushed

and remember it -- it's important for later.

Now, I'm going to flip through this deck of cards

and ask you to choose a card that you will see in the deck.

Are you ready?

Alright, now that you have your card in mind,

add the value of your card to your previous number.

For example, if you chose the six of clubs, add six,

if it's an ace, add one,

and take 11 for any picture cards.

Have you got your final number in mind?

Perfect.

So please take the item matching your final number.

Now, here's what's funny.

There are going to be a lot of people watching this video,

and you all have different quirks with different preferences.

And yet,

the vast majority of you right now is thinking about a kiwi,

or, if you're left-handed, probably a corn on the cob.

Yes, I just tricked you.

And I used your psychological biases

to influence both of your decisions.

I work in the MAGIC Lab

at Goldsmiths University of London,

which is not only a place where we make assistants vanish,

but where we use magic tricks to study psychological processes,

such as attention, perception, deception and free will.

I am fascinated by the subtle factors that influence our choices,

and how understanding our flaws can give us back some power.

Magic tricks provide a powerful tool to investigate this,

and our experiments have shown that.

First, we humans tend to go for the easiest decisions.

With the card trick I did,

most people tend to choose the card that I want them to choose,

because I'm presenting it a bit longer than the others.

And it becomes the easiest option for your brain.

In our case,

the majority of you probably chose the ten of hearts, right?

And a lot of other tricks are based on this principle

of easy decision.

Because magicians are very aware

that our brain, not to say "we," tends to be a bit lazy.

The exercise we did with the four cards is also a good example of this.

It's based on another trick I investigated,

where I ask participants to physically push

one of the four cards towards me.

We found that around 60 percent of people choose the third card from the left,

and if they were left-handed,

they typically chose the second card from the left.

This is based on the easy-option principle again,

because the card that most people choose

is the most easy to reach by the dominant hand.

So, I knew that most of you

would end up with one of these two numbers,

and this allowed me to estimate

the two most probable things you would end up with.

But this is not just about magic.

It's also about how we are influenced in our day-to-day lives.

You know, stories and politicians

play with your mind as well, all the time,

because they also know that we tend to choose and like

what's easily grabbed or seen.

For instance, when you are in a store,

choosing a bottle of wine or a bag of rice

among many lined up on vertical shelves,

your first instinct is to look

only at the ones that are on the shelves in front of your eyes, right?

It's easier and requires less effort.

Did you know that many brands actually negotiate

to be at eye-level on grocery store shelves

because of that easy-option principle?

And this is a tactic that many politicians use.

When information is right in front of our eyes on social media,

it's easily accessible,

and it absolutely affects our voting behaviors.

Political outcomes, such as the Brexit referendum

or the American election in 2016,

were heavily influenced by targeted advertising,

making some information,

which was not necessarily truthful,

disproportionately easily accessible and visible to specific audiences

to influence their votes.

But here is the good news.

Some simple factors have an impact on how influencible we are.

In an experiment using the trick with the four cards,

we found that explicitly informing participants

that they have a choice

can actually lead them to make more deliberate decisions,

as opposed to behaving in the way we are trying to make them behave.

In other words,

I either simply asked participants to push one of the cards,

or I said,

"Choose a card, and then push it."

And when asked to choose a card,

the percentage of people who impulsively chose the most reachable one

dropped from 60 to 35 percent.

So, it seems that when we are reminded that we have control over our choices,

and know that our actions matter,

as opposed to acting without thinking,

we can actually make more personal decisions

and are less easily influenced.

Let me show you another trick,

invented by a British mentalist Derren Brown,

to make my point.

This one uses what's called "priming" in psychology.

Priming happens when exposure to something

influences your thoughts and behavior later on,

without you being aware

that the first thing is guiding you to a certain extent.

The trick is usually done in a more intimate context,

where I would be directly facing you,

but we'll give it a try together.

Just focus on me as best as you can,

but do not let me influence your choice.

I'm going to try and mentally transmit the identity of a playing card

I'm thinking of.

Are you ready?

OK, so first make the color bright and vivid.

Imagine a screen in your mind,

and on the screen, the little numbers, low down in the corners of the cards,

and then in the top of the cards.

And then the things in the middle,

in the center of the cards,

the boom, boom, boom, the suits.

Did you get it?

OK, so I'm going to bet that the majority of you

thought about the three of diamonds,

but chose another card, right?

As you might have noticed,

I heavily tried to influence your choice with my gestures

while giving you the instructions.

By studying this trick,

we found that around 18 percent of people choose the three of diamonds,

and nearly 40 percent choose the three of any suit,

while being completely oblivious of the fact I was manipulating them.

So what happened here?

Because you were aware

that I was trying to influence your choice,

you probably paid more attention to what I was doing.

And this led the majority of you to choose more consciously

than our participants who have no information

about who I am, what I'm studying

or what I'm trying to do with their minds.

So the thing is,

in all of our experiments,

we managed to heavily influence people's card choices,

while they report feeling completely free and in control of their choice.

And this lack of self-awareness

makes politicians, companies

and other people's influence all the more powerful,

because we might think we are in control of our choice and beliefs

when we are not.

Politically or in our consumer behaviors,

if we don't pay attention,

misleading content or showy ads can just trick our mind.

What if, in our day-to-day lives,

we would stop more often and consciously choose

before acting on this impulsive, reactive beast inside of us?

We can actually act more consciously

if we keep in mind

that we have the capacity to be influenced.

Thank you.