A new study has revealed less than a third of Australians say they know how to support an autistic person, despite strong awareness of the condition.

Most Australians have heard of autism but less than a third of people know how to support an autistic person, researchers have revealed.

A study by Victoria's peak body for autistic people has found there is widespread awareness of the condition that affects more than one in 100 people, yet only 29 per cent of people believe they know how to support an autistic person.

When researchers asked the same question of autistic people, only four per cent of them believed people in the community knew how to support them.

The figures, released by Amaze on Monday, showed more than half of the 57 autistic people surveyed felt socially isolated and 42 per cent said they sometimes felt unable to leave the house because they were worried about people behaving negatively towards them.

"Autistic people tell us it's not their autism that disables them, it's the reactions of the other people in the community," Amaze CEO Fiona Sharkie told AAP.

"Difference should be embraced."

The findings come after a video of a horrific attack on an autistic boy in Melbourne surfaced last week, making headlines around Australia.

A teenager has been charged after the 14-year-old autistic boy was allegedly bashed and beaten with spanners by five youths outside Northcote High School on Tuesday.

Carmen Lahiff-Jenkins said her son Quinn was pushed from his bike and beaten yet "no adult stopped to help, no one beeped their horn or did anything from their cars," she told 3AW radio on Thursday.

"It's the worst nightmare of most parents who have an autistic child."

Ms Sharkie said Monday's timing of a new campaign, Do One Thing For Autism, couldn't be better.

"We're not asking people to build a rocket and discover new planets. The biggest thing people can do is not judge and criticise," she said.

While autism affects people differently, there are two common traits across the spectrum: Challenges with social communication and interaction, and particularities in behaviour, interests and activities.

Autistic people find sarcasm and idioms confusing, because they process language literally and they find it difficult to read social cues such as tone of voice or facial expressions, Ms Sharkie said.

"Don't say to an autistic person, 'give me a hand'. Say, 'can you help me lift this box onto the table?'" she said.

"If someone at work asks, 'how is your weekend?' They wonder, 'how much they should I explain? Should I say I had sex with my girlfriend?'"

Ms Sharkie also said people need to be more understanding of how environment can affect autistic people, especially locations where social gathering are common, such as cafes and sporting events.

"Autistic people can be sensory sensitive," Ms Sharkie said.

"Eating cornflakes can be like eating razor blades. Or wearing lace against their skin can feel like sandpaper."