It's no secret that most of us have a complicated relationship with our stuff.

Our homes may be loaded with more possessions than ever before, but the rise of Marie Kondo and The Minimalists shows that many of us are trying to live with less.

Meanwhile, Australian op shops have reported a rise in donations over the previous few years, as people clear out their unwanted household items.

But before they start to re-organise their lives, many people must confront why they have such strong ties to their bits and bobs in the first place.

And researchers like Bond University's Dr Libby Sander have investigated what messy environments do to human behaviour.

"Generally, what happens to our brain in a cluttered environment is we just get cognitively overloaded," she said.

Dr Sander, Assistant Professor of Organisational Behaviour, said previous studies indicated a direct link between cluttered spaces and feeling overwhelmed.

"It reduces our working memory, so it reduces our ability to focus … [and] we can't process information as well and we're just not as productive," she said.

Dr Sander and others have asked — does controlling our stuff give us more control over our lives?

How clutter affects our brain

Dr Sander points to several ways that too much stuff can produce measurable changes in our brains and bodies.

People who sleep in cluttered rooms have been shown to have more difficulty falling and staying asleep.

Children's toys can be a strain on tidying up. ( Supplied: Organize It )

She said most of us feel calmer when our environment is tidier because our brains tend to gravitate towards order.

"The more clutter we have around us, it's this constant visual reminder of disorganisation," Dr Sander said.

Cutting down on clutter may even allow us to have better personal relationships, according to Dr Sander.

She cited one study where participants watched a pre-recorded video and were then asked to interpret the emotional expression on the faces of the people in the film.

Participants watching in a cluttered room were far less likely to correctly interpret the emotional expression on the person's face.

"Despite what most of us believe, the majority of us can't actually multitask," she said.

"So if you think about it in terms of the home setting or workspace, if there is a lot of clutter around, we might misinterpret what someone is feeling or what their emotion is, and obviously that could contribute to poorer outcomes in our relationships."

How do we reduce our stuff?

Peter Walsh is a professional organiser and Oprah Winfrey's "get your life organised" guy — it's his job to advise people on how to declutter their homes.

He said he approaches decluttering with a view to making people more content.

"If you overload your space, if you fill it with too much stuff, if you don't treat your space with honour and respect, you can never be happy in that home," he said.

Indoor plants can bring a sense of calm inside the home. ( ABC Radio Brisbane: Jessica Hinchliffe )

Mr Walsh said most of our possessions fall into one of two categories: memory clutter (the stuff that reminds you of an important person, achievement, or event from the past) or "I might need it one day" stuff (the things you hold onto in anticipation of an uncertain future).

Three quick tidying tips 1. Start with just 10 minutes a day 2. Prevent clutter from happening in the first place. Ask yourself: "Does this actually deserve to live here?" or "do I really need it?" 3. Don't put it down, put it away. If you can't fit it in, you might be living with too much stuff.

"To deal with this, you really have to dig below the stuff, to work out what the stuff represents," Mr Walsh said.

"It's an emotional release, and it's interesting about the stuff we own and the impression it creates with us.

"The stuff we own exerts some power over us.

"And letting go of our stuff means letting go of a dream, letting go of a perception of our self, embracing a future self that may be unclear or we're uncertain of, and that's the power of our stuff."

To help unpick all those years of clutter conditioning, Mr Walsh suggested one simple tidying trick to kickstart the process each day.

"If you want to stop clutter, don't put it down, put it away," he said.

"That will turn your house around in a week."