A new survey from TD Ameritrade finds that most younger Americans are starting to save for their retirements at a much earlier age than their parents did to avoid having to rely on social security or other income sources in their golden years.

The survey of 2,001 members of Generations X, Y and Z (people between 13 and 22 years of age) revealed that 59% of Generation X and 56% of Generation Y make regular, automatic contribution to their retirement savings compared to only 46% of non-retired baby boomers.

Moreover, these Gen X and Gen Y investors are starting early. On average, these two groups began saving for their retirements in their mid-to-late 20s - a full decade earlier than baby boomers who, on average, began building their nest eggs at age 35.

"For even the most sophisticated investor, retirement planning can be a tough concept to grasp," said Carrie Braxdale, managing director of investor services at TD Ameritrade. "Gen X and Y have accepted the reality of the past few years, and rather than being discouraged, they are using what they've witnessed to their advantage by saving earlier and regularly."

"The hope is that tomorrow's investors, Gen Z, follow suit as they near retirement," she added.

But that might be wishful thinking - at least according to early returns.

Generation Z, the group who grew up in households that struggled through the recession and housing market collapse, is a little too young to really appreciate the importance of retirement savings. Only 8% of this group has initiated any kind of retirement savings plan.

Of this group, 35% of Gen Zers believe they won't be able to count on social security when they retire compared to 61% of their parents. However, 39% of Gen Z respondents said they're expecting an inheritance and, therefore, don't need to worry about saving for retirement.

"The good news is that Gen Z is starting off with a good understanding of the importance of saving," Braxdale said. "But that doesn't mean they should wait to become more educated on proper long-term savings habits."

Larry Barrett writes for Financial Planning.