Millennials have a certain reputation for being the most interested in investments that also do good for the world.
The investment research firm found that a majority of the U.S. population — 72% — is interested in investing in environmental, social and governance funds.
Morningstar also found that millennials and Generation X were "statistically equivalent" when their level of interest in sustainable investing was scored.
Meanwhile, millennials had a "slightly stronger preference" for these investments compared to baby boomers.
More from Impact Investing:
Homeowner avoided 'energy guzzlers' for more efficient options
Can you save money and the planet by owning a Tesla?
Investing with equal pay in mind more difficult than you think
The research also debunked another common misconception: That women are more interested than men in putting their money in investments that also do good.
Women did show a slightly stronger preference for sustainable investments, the research found. But the difference between the weighted averages of the scores assigned to the genders was small.
"A lot of people care about sustainability," said Ryan Murphy, head of decision sciences at Morningstar Investment Management and a co-author of the research. "This is not just a fringe preference.
"The idea that this is of interest to a subgroup doesn't really hold."
Part of the misconceptions that women and millennials are most interested in sustainable investing comes from the way the research is conducted, according to Morningstar.
Most surveys typically ask investors to show their interest in these investments in a certain way, for example by rating them from one to five. In this format, respondents may be more tempted to answer in a way that reflects what they think others want to hear.
"No one wants to say I'm not interested, because that seems cold-hearted," Murphy said.
In its research, Morningstar instead asked respondents how they would allocate $1,000 between two investment choices. That included Monster Beverage, with a low sustainability rating and 29.15% annualized five-year total returns, versus Walt Disney with an average sustainability rating and 18.22% returns.
Based on their answers, respondents are then given a sustainability preference score, which ranges from zero to 100.
Morningstar applied used this scoring method to profile 948 respondents. Through that research, the firm found that 72% of the population is at least moderately interested in sustainable investments.
Even research that skews toward millennials can show that all generations have some interest in socially responsible investing.
A recent survey from TD Ameritrade found that out of 1,056 adults with at least $250,000 in investable assets, millennials were most likely to consider socially responsible investments, with 43%. Still, 33% of Gen Xers and 25% of baby boomers showed interest in those investments.
"What our survey findings tell us is it really is of interest to all of the generations," said Samantha Newsom, manager of investment and digital guidance at TD Ameritrade.
There are some key differences in the causes these generations care about, Newsom said. Millennials are more focused on environmental and human rights. Boomers, on the other hand, care more about diversity and religion.
Another key factor determines how much each generation is willing to invest in these initiatives: their investment time horizon.
"Older generations, boomers, are at a different stage of not only their life cycle, but their investing cycle," Newsom said. "They're thinking more about retirement right now, versus millennials are just now getting started on their investment journey."