Today's young millennial voters are seen as a key demographic for political victory in many races this fall. Now, new research suggests that millennials' political views differ significantly from young people from previous generations.

A team led by San Diego State University psychology professor Jean Twenge, author of the book "Generation Me," examined data from three large, nationally representative surveys of high school seniors, entering college students and adults in the United States administered since the 1970s. The surveys included responses to a variety of political questions from 10 million participants.

As of 2014, nearly half (46 percent) of adult Americans identified as political independents, including 59 percent of Millennials ages 18 to 29. Both of those numbers are all-time highs.

"Americans, especially young people, are abandoning the two major political parties to declare themselves politically independent," Twenge said. "In an increasingly individualistic culture, large groups such as political parties are less popular."

"Independent" doesn't necessarily translate into politically moderate, however. The researchers also found that political views have become more polarized in recent years, with twice as many adults in the 2010s describing themselves as either extremely liberal or conservative than adults in the early 1970s.

Those who do claim allegiance to one of the two major political parties in the United States are more homogenous in their views. Whereas there were once liberal and conservative members of both parties, today the vast majority of those who identify as Republicans hold conservative views and those who identify as Democrats hold liberal views, the study found. The researchers published their work in the journal Personality and Social Psychology Bulletin.

In recent years, there has also been an uptick in conservatism among young people. High school seniors in the 2010s were 38 percent more likely to identify as conservatives than their age-matched peers in the 1970s. That's surprising, Twenge said, because these same young people disagree with many traditionally conservative viewpoints, indicating a potential overhaul of the definition of conservatism.

"Given young people's support for same-sex marriage and legalizing marijuana, it's surprising that more now identify as political conservatives," she says. "It may be that the definition of what they consider conservative is changing. Overall, Millennials may not be as reliably liberal and Democrat as many had predicted, especially as they are likely to grow more conservative as they get older."