If you put a bird in a cage, it can't fly. But the minute you open the door, it has a world of opportunity to explore.

How many times have you looked at someone and immediately judged them? We all do it, all the time. It's part of human nature.

But for most of us, the first impression we leave with someone is completely different with each person we meet.

Imagine if everyone you ever saw looked at you and thought "unintelligent, socially inept, completely incompetent". Imagine trying to break out of that cage of expectation.

Charles M. Schwab, an American steel magnate, once said: "When a man has put a limit on what he will do, he has put a limit on what he can do." The expectations of other people, believe it or not, are one of the most inhibiting factors in someone's success.

In order to do well, there must be someone who genuinely believes in you. There is no one that "can't" do something. We choose not to.

With enough hard work, anything is possible. This is probably one of the most valuable lessons I have learnt from growing up with a sibling who has Down syndrome.

When my little sister was born, the doctors told my parents she might never learn to run and jump, and would certainly never ride a bike or be like other children. I wish they could see her now, 15 years later.

My sister's life has been an amazing journey, jumping from one impressive accomplishment to the next. At 2 she learnt to read, she was riding a bike without training wheels at 6, she became quite fluent in French at 7 and, most recently, she passed NCEA Level 1 trigonometry in Year 10.

None of this would have happened without parents and family who believed it was possible.

I think my sister has proved, not only to herself and her family, but to anyone who has been in close contact with her, that many common beliefs about people with Down syndrome are false. Most new parents of children with Down syndrome just accept doctors' "expert knowledge" and their gloomy prognosis then becomes a reality. However, with the right support and attitude, a Down syndrome person can achieve much more than most people would imagine.

In Russia, until a few years ago, people with Down syndrome would be shut up in a special hospital from birth. They spent their entire life in a tiny room furnished with just a cot. They had little human interaction, with maybe two nurses per 100 patients, and were not taught to read or write.

My sister wrote a petition and a truckload of letters, including postcard reproductions of her own, that were sent to Vladimir Putin as part of an Amnesty International campaign to pressure Russia's government to respect these people's human rights. These people had no quality of life and never got anywhere because that was what was expected of them.

Had any Russian Down syndrome person had someone to believe in them, who knows what they may have achieved? Instead, they were confined to being prisoners, without committing a crime, and their lives passed by, no one caring, and nothing to remember them by.

Even in countries that have conducted substantial research on people with Down syndrome, expectations of their abilities and potential are still very low.

Children will always grow up to be what is expected of them. Children expected to be smart will work hard to ensure they remain on top of their class and children expected to become exceptional musicians will practise every day to make that a reality.

Children who are expected to not achieve much never will reach their potential.

There is a social responsibility to look after people with disabilities so we should stop enforcing a generalised expectation.

Judge each person as an individual, believe in them and help them to be the best they can. So long as we are open to the unexpected, there will always be success.

Dijana Sneath, Year 13, Glendowie College

By Dijana Sneath