the average score on IQ tests across the world grew significantly.

Does this mean humans are getting smarter?

Is intelligence going to keep growing?

And what will intelligence mean in the future?

Will emotional intelligence, showing understanding of others,

be considered more important than abstract logic?

Will humans be eclipsed by intelligent machines?

We asked some of the planet's leading intelligence experts

to share their views.

During the 20th Century, IQs around the world

increased 30 points, which is huge.

The difference between 100 and 130

is the difference between someone ranked as average

and someone rated as gifted,

and so what that shows is clearly intelligence can be increased.

Academic intelligence or analytical intelligence can be increased.

Creativity, you learn by having good parenting and good schooling

that encourages you to be creative.

And common sense you learn from the mistakes

you and others make in your life and how to fix them.

Increasing quality of nutrition, better education,

and greater exposure to more new technologies

are all factors behind our increasing intelligence -

but will we ever hit a limit?

It's pretty clear we won't

because we're going to keep on

finding problems, creating problems,

that require new tools and we're going to keep the old toolset

and get some new ones and that's been going on

ever since the industrial revolution.

I don't know if we'll reach the limit of human intelligence

because we don't know what the limit is.

The one thing we can be pretty sure of

is that we all could do much better than we're doing,

so regardless of what that limit is

people could be much smarter if they focused on,

"How can we make the world a better place?"

We have no idea what the limit of human intelligence might be.

I think in society today

we've only scratched the surface

on our intellectual capacity

and we will continue to grow.

Moving forward I'd like to see us...

embrace the notion that intelligence is truly malleable,

that we can grow and develop and get smarter.

But not all our experts agree.

I don't think intelligence is rising at all

and I don't think it has risen for a very long time.

The earliest humans like us with our brain capacity go back 315,000 years

and we know now that those people were involved in long distance trade.

Go back 100,000 years and people were developing paint workshops

and a little bit later

they were developing plaques with abstract symbols.

Those people were clearly modern human beings

with intelligence like ours.

I don't think intelligence has changed since then.

One issue with trying to determine

whether intelligence is increasing or not is how we measure it.

IQ tests focus too specifically

on abstract logic to tell us everything we need to know

about a person's intelligence

So maybe we're looking at intelligence the wrong way.

Perhaps it's time we stopped thinking about intelligence

as an inbuilt quality we each have

but as something more fluid.

I would like to see society...

place less emphasis on intelligence as it's conventionally defined

because basically it's very much viewed as individual,

whereas in fact most of what we do in the world is in groups

so we work in teams, we work in groups,

we work together mutually to solve problems.

I think we need, as a society, to put more emphasis

on real-world intelligence

How do you use - whether it's your IQ or your creative intelligence,

how do you use these kinds of knowledge and skills

for a common good?

If we start to think of intelligence as a way of improving the common good

we also need to ensure that everyone's perspectives are included.

The neurodiversity movement,

which has been growing exponentially in the last few years,

makes the argument that individuals

with different kinds of neurological capacities

should not be excluded but should be integrated into society

because they have so much more to benefit that society.

It was developed by autistic activists

who argued that autistic people,

people with intellectual differences,

all people had the capacity to shape and change the world.

Somebody like Greta Thunberg is a perfect example

of someone whose different style of thinking

has led her to be able to...

It may be that we can all come together

to use our different forms of intelligence to improve the world,

but what about artificial intelligence?

Are we likely to be out-thought, out grown,

or even replaced by intelligent machines?

I would say that artificial intelligence and human intelligence

really are two completely separate phenomena.

I would say that artificial intelligence really isn't bound

by the limits of human intelligence, for better or worse,

and so there may be things that humans remain better at

and things that artificial intelligence is better at.

I think one of the great fallacies is the whole idea

of using computers as analogy to brains.

Our wet, organic brains are very, very different from computers.

The kind of intelligence we have is responsive to environment

in a way that a computer isn't

so I don't think computer intelligence and human intelligence

are in any way comparable.

Well that's a relief.

So although AI will change so much about our world

it sounds like our old wet brains won't be eclipsed.

And while our experts don't all agree

that our species will keep getting smarter...