Make the most of your tax refund with this mental hack, says senior behavioral researcher

The average amount of this year's tax refund — over $3,000 so far — means many Americans can look forward to a decent chunk of cash landing in their bank accounts. And while you know that windfall from the IRS can help better your finances, it's hard to resist spending your refund. But a psychological hack can make doing the smart thing a little easier.

Judson Bonick, a senior behavioral researcher on the Health Team at Duke University's Center for Advanced Hindsight, suggests focusing on what he calls our "intention-action gap" — in other words, the gap between what we intend to do and what we actually end up doing.

"It's all too common that even the best intentions often don't translate into actions," Bonick explains. "I'm definitely guilty of this. Most mornings, I promise myself I'm going to exercise 30 minutes that day. Most nights, I ask myself why I did not keep that promise."

CNBC Select asked Bonick to share his tips on how you can make a meaningful promise you'll keep when it comes to making the most of this year's tax refund.

Before you receive your tax refund, make a detailed pledge to use it in a way that makes sense for your finances. "[A pledge] will increase your chances of spending your money based on your best intentions and not your spur-of-the-moment impulses," Bonick says.

This isn't just Bonick's opinion. His previous research found that more people donated a portion of their Covid stimulus checks to charity when they made a pledge to do so, compared with people just reading an article about donating their stimulus checks.

To create a pledge about your tax return with similar effectiveness, it should try to have the following:

A specific destination for your refund money

Instead of just saying, "I want to use my tax refund to increase my savings," you can be specific about where you want to put that cash and the amount you're willing to commit from your tax refund. For example, smart moves to make include paying off high-interest credit card debt or putting that cash into an above-average high-yield savings account, such as any of the below:

When it comes to deciding how much of your refund to put away, Bonick suggests making the math easy: For example, decide to put 50% of your refund into a high-yield savings account or use $1,000 of the refund cash to pay off debt. By outlining it this way, you can also designate a portion of your refund from what's left over to treat yourself.

A plan of action

To give yourself the best chance of closing your intention-action gap, try taking some steps before the money actually comes in, Bonick suggests. Depending on your plans, that may look like already having the high-yield savings account or an individual retirement account (IRA) open before the refund arrives.

"You should go ahead and do all you can now," Bonick says. "The more actions you take before receiving your refund, the more likely you'll be to achieve your pledge."

Outside accountability

There's no better way to make something official than by putting it in writing. Bonick recommends taxpayers write down their pledges and sign them.

"Put it somewhere you'll see it frequently, like stuck to the refrigerator," he adds. "Say it to yourself whenever you see it. The more you see and repeat it, the more it will become the automatic thing you do when your tax refund arrives."

By using the mental hack of closing your intention-action gap through a detailed pledge, you can avoid the natural spending impulses that come with tax refunds and use that cash for financially constructive purposes.

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