Last week, President Obama remarked that soaring oil prices did his approval rating no favors. "My poll numbers go up and down depending on the latest crisis, and right now gas prices are weighing heavily on people," he said.

He's likely onto something, and the phenomenon isn't unique to his numbers. Presidential approval ratings and oil prices have been linked for decades.

First, the standard disclosures about this stuff: Correlation doesn't mean causation. Just because high oil prices correlate with low approval numbers doesn't mean high oil prices cause low approval numbers. More likely, consumer confidence drives approval numbers, and oil prices play one factor -- albeit a large one -- in that metric.

At any rate, here's how this looks for President Obama:

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Sources: The American Presidency Project, The Federal Reserve.

Oil up, approval down. Same deal for President Bush, where the connection is even more convincing:

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Sources: The American Presidency Project, The Federal Reserve.

Oil collapsed at the end of President Bush's term, with little impact on his approval numbers. That collapse, though, was triggered by the crumbling economy -- a slash to consumer confidence itself.

You can take these numbers back several administrations. The connection isn't perfect, but it's still convincing. President Clinton enjoyed relatively stable oil prices and rising approval numbers. President Carter's approval numbers collapsed in tandem with oil's spike. Ditto for President Ford.

The results, I think, tell us more about consumer behavior than politics. They show that oil prices have an outsized effect on consumer confidence -- a phenomenon long documented by researchers.

In a way, this isn't surprising. The increase in average gas prices today compared with a year ago costs consumers more than $100 billion annually, or roughly $1,000 per household. That's real money, even if such spikes are almost always short-lived.

But there's more to it. MIT economist Dan Ariely points out that the way we buy gasoline affects us in ways other products don't:

For the several minutes that I stand at the pump, all I do is stare at the growing total on the meter -- there is nothing else to do. And I have time to remember how much it cost a year ago, two years ago and even six years ago. Yet I have no such memory about the prices of items in any other category. I have no idea how much milk was six years ago, how much bread was three years ago or how much yogurt was a week ago.

Then there's the way the media reports on oil prices. When prices rise, the media commonly responds by unanimously pointing its fingers at ExxonMobil (NYSE: XOM), BP (NYSE: BP), and Chevron (NYSE: CVX), assuming they must be to blame. Those profits, you see! But this argument is just as flawed today as it was in 2008. Domestic oil companies are responsible for a pittance of global production, and they operate with fairly low profit margins. Despite this truth, the media's blame game makes consumers feel victimized.

All of this noise causes us to react irrationally. To see what I mean, go to Costco (Nasdaq: COST) on a busy weekend. Most Costco warehouses sell gasoline for a nickel or two less than other local gas stations. When gas prices spike, people often wait for an hour or more to fill their tank with Costco gas. The savings most of these folks will see compared with an open station across the street is a dollar or two, max. Is their time really worth so little?

Same goes for those attempting to save money by trading their traditional cars for hybrids. Hybrids aren't cheap, easily costing $10,000 more than comparable all-gas models. Even for hardcore commuters, it could take years for the savings achieved from better gas mileage to pay for that investment, if ever at all. You don't see that kind of reaction when the price of, say, electricity or health insurance rises.

That's the mysterious force oil plays on us -- we often overreact to its consequences with more disproportionate fervor than we would to the price movements of other goods. This makes it particularly troublesome for politicians, whose fate might be tied to oil prices.

A sensible question, then, is how much of oil's surge we can blame on politicians themselves. I'll leave that one up to you to answer, but here are a few points to consider.

A weak dollar does raise the nominal price of oil, but it's probably not as big a factor as some assume. The U.S. Dollar Index was recently near the same level it hit in the mid-'90s, yet the price of oil, even adjusted for inflation, is four times as high. Meanwhile, commodity index holdings were $317 billion in 2008, up from $13 billion in 2003. A decade ago, China consumed less than five million barrels of oil a day; today, it consumes more than 10 million. At the same time, oil investors position their money to fit an economy that is, at least in part, guided by political policy.

What do you think? Are presidents to blame for higher oil prices? Sound off below.

Fool contributor Morgan Housel owns shares of Exxon. Follow him on Twitter @TMFHousel. Costco Wholesale is a Motley Fool Inside Value selection. Costco Wholesale is a Motley Fool Stock Advisor pick. Chevron is a Motley Fool Income Investor pick. The Fool owns shares of Costco Wholesale, and ExxonMobil. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.