NEW YORK (MainStreet) — Alicia Phillips, a 28-year-old in San Jose, Calif., who does marketing for a start-up, is forgoing all retirement planning. She has $125,000 in student loans from Rowan University in New Jersey and Duquesne University Law School, which she left last year. A 401(k), she says, would be futile.

“I figure with that debt, plus the mortgage I'll eventually have and children I'll potentially have — I'll spend my entire life barely paying my bills and have to work well beyond retirement age,” she says.

Yet even if she had the extra money, she wouldn’t make investments she could reap the benefits of only down the line.

“More likely I'd make some risky investments hoping for big returns and travel more,” she says. “Not the smarter decision, but I'd rather experience more of life, then worry about supplementing Social Security insurance payments 50 years from now — if I even get those.”

Phillips is not alone in her focus on “the now.”

There are clear reasons behind why 20- and 30-something guys and gals are not contributing as much to 401(k)s: it's simply not in the caveman wiring to think 40 years ahead, according to behavioral economists such as Teresa Ghilarducci, director of the Schwartz Center for Economic Policy Analysis in the Department of Economics at The New School. “Young people, because of their age, do not have the DNA to worry about their old age, because as a species we’ve been very concerned about survival,” Ghilarducci says. “Saving for your old age is not what geneticists call a selective factor, and those who worry about their old age may not have children.”

It’s a major feat to overcome this predisposition and biological imperative. The numbers prove it.

In the U.S., companies have $1.5 trillion in unfunded or underfunded pension obligations. Almost half of Americans have less than $10,000 in retirement savings, with almost a third with less than $1,000. In total, American workers are $6.6 trillion short of what they'll need to retire. And the idea of a true Florida golf course/no-job retirement seems old hat: Almost three-quarters of people will maintain some job after retirement, and close to half will work until death.

“We have to overcome with our intellect the biological imperative to reproduce,” Ghilarducci says. “You have to channel that ability to emphasize your lifemate and your own older self.”

J. Andrew Hammond, a 28-year-old financial adviser at Northwestern Mutual, says that’s not as easy as it sounds.

He has seen “countless” cavemen types who would rather put a down payment on a home (shelter) now than think about down the line.

The solution?

The stakes are high, with 10,000 baby boomers set to retire each day for the next 20 years. This concerns Chad Parks, CEO and founder of The Online 401(k), a retirement plan provider for 5,000 businesses in the U.S.

“If you think about the human race, we are not biologically planned to think about a long term,” Parks says. “We are focused on short-term, immediate survival needs. There’s a hierarchy of needs. Food and shelter are wired into our brains. Those come first. Can we think about our needs 30 or 40 years down the road?”

“Human nature is very much procrastination oriented,” he says. “Even people losing weight, going to the gym. Those industries face the same challenges: There’s no immediate gratification for long-term retirement savings. You look at your account. Maybe it has $1,000, $5,000, $10,000. Doesn’t seem like a lot.”

The solution, he believes, hinges on making retirement savings fun through “gamification” to curb the inherent human nature resistance to it.

“How can we create an experience that ties to individuals’ goals that rewards them in the short run for what’s good in the long run?” Parks says. That may come in setting something up in a Zynga-like platform, he says, to give users the illusion that saving for retirement is fun. Right now, he views the situation as grim.

“What’s wrong with you?” he says. “You won’t spend a dollar on your retirement but you will buy a fake cow for your fake farm with real money.”

Parks has actually spent a considerable amount of time in Tanzania among the Hadzabe tribe, a hunter-and-gatherer society.

“Even though we have evolved,” he says, "we still are the same at heart.”