A new study purports to show that the conservative brain has an overly large fear center, while the anterior cingulate associated with courage is smaller than average. That might explain the continued cowardice of Republican leaders when it comes to offering specifics on the spending cuts they claim to support in the face of mounting debt they only recently came to fear.
To be sure, there's no shortage of tough talk on spending from a GOP playing a dangerous game of chicken over the U.S. debt ceiling. This week, incoming Kentucky Senator Rand Paul announced, "I think that every piece of major legislation that goes forward from now on needs to have attached to it spending cuts." Appearing on Fox News Sunday, Tom Coburn (R-OK) warned of "apocalyptic pain" due to future deficits and claimed, "There's well over $300 billion a year that I can lay out for you in detail that most Americans believe we should eliminate." And, as CNN reported, House Speaker-to-Be John Boehner is promising to keep his GOP Pledge to America, declaring "slashing the federal budget by $100 billion will be priority number one."
Unfortunately, Boehner like his Republican colleagues won't say how.
As CNN noted:

Asked which programs will be cut to get to the $100 billion target, Boehner did not offer specifics.
"But I will tell you," he told reporters earlier this month. "We are going to cut spending."

But as the New York Times and Bloomberg previously explained noted, the GOP's promise to immediately return to pre-recession FY 2008 levels for "non-security discretionary spending" with would result in devastating cuts to popular and needed programs. With the Pentagon, Social Security and Medicare off the table, those draconian cutbacks would slash more than 20 percent of spending by departments like Education, Transportation, Interior, Commerce and Energy:

U.S. House Republicans' pledge to cut $100 billion from the federal budget next year would slash spending for education, cancer research and aid to local police and firefighters.
Keeping the midterm-campaign promise would require a Republican-led Congress to cut 21 percent of the $477 billion lawmakers have earmarked for domestic discretionary spending.

As it turns out, a Republican Party almost pathologically obsessed with "cojones" and "manning up" has for months shied away from the spending cuts they dare not name.
In August, the Christian Science Monitor captured the dynamic in a piece titled, "GOP Flinching at Budget Spending Cuts Plan." Just two weeks before the November midterm elections that swept the Republicans back into the majority in the House, the New York Times reported that "As GOP Seeks Spending Cuts, Details Are Scarce." In September, John Boehner essentially confessed to the charge that "Congressional Republicans have used the old trick of promising specific tax cuts and vague spending cuts." Confronted by Chris Wallace of Fox News that "there is not one single proposal to cut Social Security, Medicare, Medicaid," Boehner lamely responded:

Chris, it's time for us as Americans to have an adult conversation with each other about the serious challenges our country faces. And we can't have that serious conversation until we lay out the size of the problem. Once Americans understand how big the problem is, then we can begin to talk about potential solutions...
Let's not get to the potential solutions. Let's make sure Americans understand how big the problem is. Then we can talk about possible solutions and then work ourselves into those solutions that are doable.

Predictably, Boehner's still not talking.

Appearing on CBS 60 Minutes two weeks ago, John Boehner shed tears over just about everything, except his still unexplained pending cuts:

STAHL: What's your first one [budget cutting measure] gonna be?
BOEHNER: Well, how about we start with cutting Congress? I'm going to cut my budget, my leadership budget five percent. I'm going to cut all the leadership budgets by five percent. I'm gonna cut every committee's budget by five percent. And every member is gonna see a five percent reduction in their allowance. All together that's $25-$30 million and it likely would be one of the first votes we cast.
STAHL: Okay, but you admit that's not very much money.
BOEHNER: You've got to start somewhere. And we're going to start there.

If symbolic spending reductions are one part of the Republican strategy deficit-cutting gambit, the other is to wait for President Obama to move first.
In November, former Bush chief of staff Andy Card urged Republicans to use President Obama and his Deficit Commission as a human shield:

"I do think it's appropriate to wait for the -- the wisdom that might come from this debt commission. They're going to have to make some tough recommendations and see how the president reacts. I think it's much too early to be talking about specific program cuts that are only designed to inflame the debate rather than be constructive and really bringing discipline to the government. The president is the one that will have to propose a budget. Congress will have to react to it."

The previous day on Meet the Press, Texas Senator John Cornyn similarly counseled Republicans to duck and cover while President Obama showed the courage they lacked:

DAVID GREGORY: What painful choices to really deal with the deficit, is Social Security on the table? What will Republicans do?
SEN. JOHN CORNYN (R-TX), CHAIR, NATIONAL REPUBLICAN SENATORS: The president has a debt commission that reports December the 1st and I think we'd all like to see what they come back with. And my hope is they'll come back for the bipartisan solution to the debt and particularly entitlement reform, as you -- as you've mentioned.
But I --
DAVID GREGORY: But wait a minute, conservatives need a -- a Democratic president's debt commission to figure out what it is they'd want to cut?

Apparently. Because after securing another massive, budget-busting tax cut windfall for the wealthiest Americans, House Republicans are touting new rules which will make future tax cuts even easier to pass and new revenue sources to balance the federal books much harder to produce. As for the details about those spending cuts promised by those cowardly conservative Republicans, Americans will have to wait for someone with real cojones to step forward first.
Like President Obama.