We take it for granted but being upright is quite a skill.

Take a normal four-legged chair - simple, stable,

or even a three-legged stool. But try a two-legged seat...

Human babies spend around 2,000 hours in their first year

developing the coordination and strength to stand.

It's the same amount of time

an Olympic athlete puts into a year's training.

Standing up is a major achievement, not only in our lives

but also in human evolution.

Why did we do this? We'll probably never know for sure

but there's no shortage of theories.

Hunters needing to take food home from the site of a kill

or conserve energy to outrun other animals.

Perhaps it was to carry and protect babies or was it for sexual display?

Some say it was our environment, as forests died back

it became easier to find food by walking than by climbing.

And the higher your head, the further you can see.

Plus being upright means less of your body

exposed to the midday African sun.

So maybe we stood up just to stay cool.

There is agreement on one thing, standing freed our hands

to become immensely sensitive and versatile tools

and with that came a big increase in brain capacity.

So from many points of view, standing is clearly a very good idea,

giving us a whole new level of control and power.

However, out of the millions of species on this planet

being a permanent biped is incredibly rare.

Some animals, baboons and bears, meerkats and chimpanzees

can occasionally pull off a two-legged trick but permanently?

Something we share with only a very few creatures on Earth.

Like some obscure rodents,

wallabies, ostriches and the giant pangolin.

Turns out this biped thing is quite tricky.

Think of robots -

tech companies have invested massively to crack this problem

of how you get a robot standing up on two legs.

And the Daleks? They don't even try.

So while they can destroy the universe,

they can't chase the Doctor up a flight of stairs.

We pay a high physical price for our standing -

chronic strain to our backs and our knees.

Truth is, standing may give us power

but it comes with exposure and vulnerability

and that's what opens it up to manipulation.

Here's an example, man and woman standing, simple.

But is it? Let's take a look at how they're standing.

The man standing firm, planted on two legs,

the woman, precariously balanced on just one.

What does that tell us?

In every culture you can find different ways that society

tries to teach us when to stand, when not to stand.

Politicians play on our hopes and fears

by telling us that we are broken or on our knees

and that they and they alone

have that magic that will make us stand tall and proud once more.

In fact we're so obsessed about standing

we talk about it all the time without even realising.

How we stand also speaks volumes about how we're feeling.

So no wonder many public speakers

like to hide their legs behind a podium

because how you're standing can reveal too much.

If you see someone looping one leg behind the other

half balanced on that point

you're going to wonder insecure, uncertain?

Or if you see someone with their hip jutted out

you might read that as quite a sexual statement.

Hands on hips? Is that reinforcing core strength and powerful

or is it perhaps defensive?

Slouching, well, quite clearly you're not exactly on top of the situation.

Changing the way you stand can actually change the way you feel

and how others feel about you.

But beware, if your stance doesn't look genuine

it may invite mockery.

Own the way you stand.

Standing is not only a state of body, it's a state of mind.