It’s been proven. Clutter is a bummer — literally.

Dishes in the sink, toys throughout the house, stuff covering every flat surface; this clutter not only makes our homes look bad, it makes us feel bad, too.

At least that’s what researchers at UCLA’s Center on Everyday Lives and Families (CELF) discovered when they explored in real time the relationship between 32 California families and the objects in their homes. The resulting book, “Life at Home in The Twenty-First Century,” is a rare look at how middle-class Americans use the space in their homes and interact with the things they accumulate over a lifetime.

Our over-worked closets are overflowing with things we rarely touch.

It turns out that clutter has a profound affect on our mood and self-esteem. CELF’s anthropologists, social scientists, and archaeologists found:

• A link between high cortisol (stress hormone) levels in home owners and a high density of household objects. The more stuff, the more stress people feel. Some, on the other hand, don’t seem bothered by mess, which accounts for tensions between tidy spouses and their clutter bug partners.

  People associate a tidy home with a happy and successful family. The more dishes that pile up in the sink, the more anxious you feel.

• Even families that want to reduce clutter often are emotionally paralyzed when it comes to sorting and pitching objects. They either can’t break sentimental attachments to objects or believe their things have hidden monetary value.

  Although U.S. consumers bear only 3% of the world’s children, we buy 40% of the world’s toys. And these toys live in every room, fighting for display space with kids’ trophies, artwork, and snapshots of their last soccer game.

Although “Life At Home” documents the clutter problem, the book offers no solutions. But there are some simple things you can do to de-clutter your home and raise your spirits.

Adopt the Rule of Five

Every time you get up from your desk or walk through a room, put away five things. Or, each hour, devote five minutes to de-cluttering. At the end of the day, you’ve cleaned for an hour.

Be Ruthless About Your Kitchen Sink

Pledge to clear and clean your kitchen sink every day. It takes a couple of seconds more to place a dish in the dishwasher than dump it in the sink. A clean sink will instantly raise your spirits and decrease your anxiety.

Put Photos Away

Return to yesteryear when only photos of ancestors or weddings earned a place. Put snapshots in a family album, which will immediately de-clutter many flat surfaces.

Unburden Your Refrigerator Door

Researchers found a correlation between the number of items stuck to the fridge door and the amount of clutter throughout the house. Toss extra magnets, file restaurant menus, and place calendars in less conspicuous places.

Test Whether You’ll Miss It

Fill a box with items you don’t love or use. Seal the box and place it in a closet. If you haven’t opened the box in a year, donate it (unopened!) to charity.

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