Thought I'd throw in a spin-ball with the whole nature vs nurture argument, as it's often used as a vague term to say "Nature being something predetermined and Nurture being something completely changing only to the thought patterns and behaviours" with the two being mutually exclusionary of the other. 

To end that thought, look up Epigenetic, this is the area were genetic predisposition is determined by the environment of the person, in other words, where behaviour that would be determined by genetics is dictated to either be active or passive determining on the environment that the person grows in. 

So, considering the political ideologies correlation with differences in brain function, it should be noted that the genetic predisposition (as opposed to a predetermination and erring on the side of eugenics), it will have little to no result on the actual brain structure of an individual past the age of 5, unless that person has a particular condition. In other words, whether your brain is on what is proposed to be a "conservative model" or "liberal model", is [b]entirely[/b] determined by environment of your upbringing. 

So, the behaviour of how genetics are expressed are directly resulting in the family values you were given (unless conflict arose out of other external influences), and the means in which your community, direct or indirect, dealt with things. 

Examples:

Impoverished individuals in urban society will usually vote more liberal as the policy of being given more financial support is mutually beneficial to them, but unlike academic liberals, will have a more right-wing attitude to social norms as a result of living in a "dog eat dog" environment. Liberal voters with more conservative minds, responding heavier to black and white, fundamental truths, traditional, orthodox understandings of the world. 

High achieving entrepreneurs will often vote conservative due to it's relaxing laws on fiscal matters, which fits in the ideology of "The economy will bring the goods with free market enterprise", but have a far greater response to novel ideas and new information, as well as exchanging communication and tolerating differing view points, which ultimately leads them to finding better opportunities within the business sector. Which shows more response to novel, ambiguous complexity in information than the traditional conservative mindset (shown by a large demographic going for a libertarian vote). 

Yet, the main tropes which are represented or caricatured are the traditional blue collar conservative vs the academic, intellectual liberal, as these are often the most polarizing of the two. Which is less a matter of necessarily the representing demographics of these voters, rather the media's means to express two opposing view points into a scalable, easily swallowed conceptual package for the general masses to gain some sort of narrative to communicate in. Problems are, it over simplifies things. Let's not make the mistake of looking at this study from a top down manner, as it only contributes to hardening the outdated and detrimental political narrative, already being overtly amplified by the competition rewarding political system at play (which, due to these problems, needs to change).