Millennials and Gen Z are divided by 9/11, an expert said. Joe Scarnici/Getty Images for #GettyGotMe

There are several differences between millennials and Gen Z, but they all begin with the key event dividing them: 9/11.

That's a ccording to research conducted by the Center for Generational Kinetics (CGK), which posits that 9/11 is a generation-defining moment for millennials.

"This is our 'Where were you when?' moment, similar to baby boomers and the JFK assassination," Jason Dorsey, a consultant, researcher of millennials, and president of CGK, told Business Insider. For a generation-defining moment to stick, he said, it must create a deep emotional connection, often associated with fear and uncertainty about the future.

"We were able to see that in order for 9/11 to be a generation-defining moment you had to remember it, feel the emotion of it, and the uncertainty of what was going to happen next," Dorsey said, adding that Gen Z is too young to remember 9/11 - most of the generation wasn't e ven born yet.

"Those born from 1996 on do not remember 9/11, and certainly not in the way those even two or three years older do," he said. "Other than the defining moment, everything else tends to be more trendlike, and you can see more of a path of continued change from millennials to Gen Z, including technology, mobile adoption, etc."

Gen Zers were born into a world with technology, whereas millennials were introduced to it. Olivia Harris/Getty

Ongoing research, he said, will help the organization discover if, when, or how these continued changes affect a generation that has grown up with these things since birth, rather than being introduced to them.

But not knowing a world without technology isn't the only difference setting Gen Z apart from millennials - Gen Z is also more social-justice-oriented, less brand conscious, and more connected to global interests and culture than millennials, Business Insider's Rachel Premack, who interviewed 100 Gen Zers, reported.

"However, it is 9/11 that is the defining and dividing event," Dorsey said. "Either you remember it and all the emotion that goes with it or you don't, and if you don't, then you're in Gen Z."

Read more: Millennials love their brands, Gen Zs are terrified of college debt, and 6 other ways Gen Zs and millennials are totally different

9/11 and the Great Recession shaped Gen Z's practical money habits

In dividing two generations, the aftermath of 9/11 created two groups with varying financial habits.

Its aftermath showed the uncertainty and fragility of the world, Dorsey said. "This, in combination with Gen X as parents and the Great Recession, [is] what we believe to be shaping Gen Z's very practical view of money," he said. "Our research into this generation shows they are much more conservative with their spending, and many are trying to graduate college with as little debt as possible."

Many Gen Zers expressed to Premack that they're worried about college debt, which is affecting where they're choosing to go to college. "Why sink yourself into exorbitant amounts of debt when you can learn everything online or learn a specific subject matter at a fraction of the price?" Tiffany Zhong, a Gen Zer who dropped out of University of California, Berkeley, to become a venture capitalist, told Premack.

Gen Z is worried about student-loan debt. Brian Snyder/Reuters

Almost 10% of teens said the key issue their generation will have to face relates to the economy and debt, according to a Business Insider survey on Gen Z.

That might be because the Great Recession marked Gen Z's childhood - the oldest of them were about 11 years old when the recession hit, Premack reported. By watching it unfold and observing its long-term effects on millennials, Gen Z became mindful of financial issues.

As teenagers, they're already saving money for "emergency funds" via mobile apps, choosing thrift stores over malls, and, in one CGK study, 12% said they were already saving for retirement, according to Dorsey.

Read more: The Great Recession split the millennial generation down the middle, creating 2 groups with very different financial habits

Millennials are taking longer to build wealth than Gen Z

While the Great Recession has also defined the financial habits of millennials, it did so in a slightly different way because millennials were directly affected by it.

Unlike Gen Z, older millennials grew up during a healthy economy, only to enter the job market as the recession hit. They had to delay traditional markers of adulthood, such as marriage and children, and building wealth - they weren't able to save or accumulate the amount of wealth they anticipated, especially if they didn't move to markets where job prospects were better or wages were enough to allow for savings, Dorsey previously told Business Insider.

Older millennials are behind on building wealth, while younger millennials are risk-averse and practical with money. Getty Images

Younger millennials experienced the recovery period and were able to learn from the older millennials who bore the brunt of the recession, according to Dorsey. This has made them risk-averse and practical with money, from saving for emergencies to contributing to a retirement account, he said.

While Gen Z and millennials share this practical approach to money, Gen Z is simply beating millennials to the same landmarks: They're building wealth and financially preparing for the future earlier.

Ultimately, while many millennials are playing catch-up with their finances, Gen Z is increasingly trying to get ahead of the game.

NOW WATCH: Popular Videos from Insider Inc.