Earlier this month, science and politics journalist Chris Mooney came out with a new book entitled The Republican Brain, The Science of Why They Deny Science—and Reality, a book that is much more insightful and objective than its partisan title would suggest. In the book, Mooney links a number of genetic and physiological studies that paint a picture of the differences between how liberals and conservatives think, and how these differences affect our behavior.

The studies prove empirically what many of you have probably already assumed: Differences in political ideology tend to arise from real differences in people’s brains. Studies have begun to show that liberals and conservatives have fundamentally different patterns of how they perceive the world and how they respond to those perceptions. These psychological differences that help shape core values and beliefs “spill over” into many different areas, politics included. In sum, psychological differences in the way we think result in personality traits that predispose us to supporting one ideology or another.

The findings prove that there is actually a lot of truth to many political stereotypes. For example, a 2003 study by John Jost found that people who scored highly on a scale measuring the fear of death were almost four times more likely to hold conservative views (The ignorant, God-fearing Republican stereotype). On the other hand, those who expressed interest in new experiences tended to be liberal (Those God-damned free-loving hippie stoners). Jost even found that conservatives prefer simple and unambiguous paintings, poems and songs (country music, anyone?).

Other studies have begun to show how deep-rooted psychological reasons explain these differences. A 2012 study by the University of Nebraska—Lincoln measured the emotional response to different images by measuring the subjects’ sweat gland response compared to their eye movement when shown different images and found that conservatives had much stronger reactions to negative images (such as a spider crawling on a person’s face or maggots in an open wound), while liberals had stronger reactions towards positive images (a smiling child or a bunny rabbit). Conservatives’ eye movements were more quickly drawn to the negative images and spent a longer time fixated on them, while liberals spent more time looking at the positive images.

These behavioral differences are likely caused by actual physical differences in conservative and liberal brains. A 2011 study at University College London took MRI scans of the brains of 90 young adult volunteers. They found that liberal students tended to have larger anterior cingulate cortices, an area of the brain that processes conflicting information, while conservatives tended to have larger amygdalas, an area that processes fear and identifies threats.

When you apply these findings to conservative and liberal ideologies, everything begins to fall into place. Thinking about any issue and how it is portrayed by liberals and conservatives, chances are that liberals will focus on positives while conservatives focus on negatives. On abortion, conservatives frame the issue with the negative imagery of baby-killing (if you are not “pro-life,” then you must be “pro-death”). Liberals frame their arguments positively with the “pro-choice” idea of women’s “freedom to choose.” On gay rights, liberals focus on the positive images of tolerance and acceptance while conservatives focus on the (subjectively) “disgusting” image of anal sex and the “destruction of family values.” On Obamacare, liberal arguments are framed on the positive image of helping others achieve access to health care, while conservatives focus on the negative ideas of declining quality of care, with some even going so far as to claim that the law would result in “death panels.” Liberals find conservative assertions like the “death panels” laughable, but this growing body of research shows that these fear-evoking assertions actually hit home with many conservative voters and are an effective campaign strategy for conservative politicians.

Mooney contends that liberal reactions to positive imagery, along with larger regions of the brain that process conflicting information lead to much higher degrees of openness, a personality Mooney defines as “a broad personality trait that covers everything from intellectual flexibility and curiosity to an enjoyment of the arts and creativity. It denotes being experimental, a risk taker in one’s way of living and one’s choices, and wanting to sample variety across the range of life’s experiences.” Respondents who scored highest in “openness” had more liberal ideologies than 71 percent of the other respondents.

Political conservatives, on the other hand, tended to rate higher in “Conscientiousness” ratings. Mooney states, “Those who rate high on this trait tend to prize orderliness and having a lot of structure in their lives — being on time, working hard, sticking to a predictable schedule, and keeping one’s home or office neat or clean. … The conscientious are highly goal-oriented, competent, and organised — and, on average, politically conservative.”

Obviously, just because you are goal-oriented doesn’t necessarily make you conservative, or a risk-taker a liberal (look at rodeo jockeys). However, I can’t help but notice some striking similarities in my own life: Two of the most organized, cleanest people I’ve ever met were two conservative frat bros I lived with sophomore year (frats don’t typically conjure up images of cleanliness), while try as I might, my own room seems to always trend toward entropy.

Mooney’s book reveals plenty of interesting trends and makes us reconceptualize political ideology. It does not however, tackle the explanation as to why liberal and conservative thinking is so different. Next week I’ll lay down a theory that attempts to explain how these differences arise due to the counterintuitive idea that conservatism represents a collectivist society, while liberalism is more individualistic. Daily Nexus columnist Riley Schenck will also elaborate on the conservative yet cleanly frat-star conundrum next week.