Can just about anyone still become a millionaire?

Two decades ago, a book called “The Millionaire Next Door” upended conventional wisdom about this small group of wealthy Americans.

Co-written by Thomas J. Stanley and William Danko, it was based on extensive research with millionaires, who weren’t actually flashy types who lived in big houses and drove expensive cars. They worked in ordinary professions such as farming and manufacturing. They drove old cars and rolled their eyes at fancy watches and lavish lifestyles.

Take the case of Robert Morin, a librarian who passed away last year at the age of 77. Morin drove a 1992 Plymouth, ate frozen dinners and found his entertainment in reading every book in chronological order that had been published between 1930 to 1938. When he died, many were surprised that he left an estate worth $4 million, his employer and alma mater, the University of New Hampshire, said in a statement last month.

Morin may fit into the mold of “The Millionaire Next Door” because of his frugality, but he also came of age when a college education -- essential to higher lifetime earnings -- was much less costly to earn. Back in 1963, the year Morin graduated from UNH, the annual cost of tuition, room and board was roughly $9,600, adjusted for 2012 dollars, according to the National Center for Education Statistics. But students enrolling in 2012 faced annual tuition, room and board of almost $24,000.

That alone means many college-educated millennials are starting off their careers with the handicap of high student loan repayments. Add in spiraling health care costs, lower incomes and expensive real estate in major cities like New York and San Francisco, and it’s no wonder that many financial experts doubt whether millennials will be able to emulate the baby boomers and older generations in building wealth.

Millennials aren’t known to be a sunny bunch when it comes to finances, but they might not be as realistic as they should be. Wells Fargo (WFC) published a survey last month noting that only about three out of 10 millennials believe they’ll secure $1 million in savings in their lifetimes. 

That may seem gloomy until one compares millennials’ expectations with the actual population of millionaires. Only one out of 10 American households have assets of at least $1 million, according to the Federal Reserve’s Survey of Consumer Finances. Rather than too glum, millennials may be too starry-eyed about their financial futures.

Despite the changes over the past few decades, some characteristics of the wealthy identified in “The Millionaire Next Door” haven’t tarnished with age, such as living frugally and focusing on planning and cultivating financial investments. Regardless of income or age, several common behaviors help build wealth, said Sarah Stanley Fallaw, the daughter of co-author Stanley and the founder and president of the research firm DataPoints.

“Interestingly enough, one of the things my dad talks about in the book was that financial professionals weren’t really interested in talking with clients about being thrifty or frugal, but for younger folks that can really make a difference,” Fallaw said. “Ignoring what the Joneses are driving and wearing -- those things are still really important.”

Another societal change is creating a headwind for consumers: It’s much, much harder to ignore feeling envious about your friend’s expensive European vacation, thanks to the ubiquitous presence of social media. That may increase pressure to keep up with the neighbors (or far-flung friends), which can lead to overspending.

Another difference, Fallaw pointed out, is the now commonplace practice of adult children moving back in with their parents after college. One of her father’s findings was that millionaires had adult children who were economically self-sufficient. Today, more young adults are living with their parents than with a spouse or partner, marking a social tipping point.

“It’s a tough choice,” Fallaw said. “For parents, it’s a pattern of behaviors in how we’re dealing with children and how much we provide to them.”

Economic research is increasingly examining how background can handicap one’s chance of securing wealth. And “chance” is the right word because aside from personal traits such as persistance and frugality, an element of luck is involved, ranging from one’s race, household income and health. White and Asian Americans are much more likely to become millionaires than blacks and Hispanics, the Federal Reserve Bank of St. Louis found earlier this year. One of its economists called it “the birth lottery.”

Here are the four traits that Fallaw’s research has identified as conducive to building wealth.

Confidence: This trait helps people stay the course in their investments, although overconfidence can be harmful if it leads to frequent trading, poor investment decisions and overestimating an asset’s value. Confidence means believing one has the skills to build and maintain wealth.

Frugality: Living below one’s means may be harder today than in previous decades, but it’s essential to build wealth. 

Responsibility: Simply put, this means taking ownership for your own financial management and outcomes. It ties back into Stanley’s finding that millionaires relied on neither inheritances nor help from their parents, nor provided economic assistance to their adult children.

Social indifference: If you can ignore the desire to keep up with the Joneses, you’ve got this covered. Still, humans are social animals, and the pressure to do what one’s friends and family members are doing can be hard to resist, especially with Facebook (FB​) making it seem as if everyone else is going on more glamorous vacations than you. 

“You can open up Facebook and see where your friends went for spring break,” Fallaw noted. “Social media and media in general is distracting people from spending time thinking about their financial future.”