We might all breathe a sigh of relief now that the election rancor has abated – but it won’t last. We are still a nation that is bitterly divided along ideological lines that pit conservative against liberal. Many such battles plumb deep-seated fault lines that go far deeper than, say, LePage vs. Michaud. Contemporary research is pointing to deep biological factors – including genetic factors – that form at least some basis for conservative vs. liberal political leanings. Conservatives and liberals are, in a real sense, becoming different species.

Brain mapping research is a hot new field that is rapidly advancing our insight into the structure of thoughts as expressed in electrical activity in the brain. Extensive use of fMRI (Functional Magnetic Resonance Imagery) reveals certain regions in the brain that are more active than others when study subjects are prompted by various cues to direct their thinking a certain way. Research then proceeds by fine-tuning the relation between what a subject is thinking and how electrical patterns appear in the brain.

A 2011 study from University College of London probed the idea of conservative versus liberal brains and set out to map brain wave activity differences the two groups as both screened and self-identified “true” liberals on the one hand, and “true” conservatives on the other. The researchers had hoped to find consistent brain activity patterns that could distinguish the two groups when given the same prompts. What they found surprised them. Not only were brain activities different, but brain anatomies were different. The “liberal” brains had higher gray matter volume in the anterior singulate cortex than the “conservative” brains. This region is associated with cognitive function including empathy, complex decision-making, error detection, and reward anticipation. “Conservative” brains, by contrast, exhibited a markedly larger right amygdala than the “liberal” brains. The right amygdala is associated with fear and negative emotions, and to taking action, both as expressions of “fight or flight” thinking.

An independent follow-up study published in 2013 found similar results among U.S. liberals (as Democrats) versus U.S. conservatives (as Republicans). This study suggested that brain wave activity in the cortical insula versus the right amygdala was a better predictor of partisanship in young adults than the political leanings of the parents and the home environment.

It is possible that some or even most of the research subjects “grew” their differing brain anatomies through environmental factors in their lives that influenced their political thinking in a certain way. But even if only a small percentage of these anatomical differences are expressions of genetic inheritance, then over time this difference can grow within a population.

The evolutionary process by which new species emerge depends on two factors only – first, that there is a distinct genetic difference between two groups within a population, and second, that this genetic difference is expressed in the organism in such a way that the two groups do not tend to reproduce. Sometimes this barrier to reproduction is geographic, and many classic cases of speciation (the process of new species formation) evolved in this way. But other cases of speciation involve barriers to reproduction within the same population.

The same week that the 2011 study on brain anatomy was released, another study appeared in the “Journal of Politics” in which thousands of spouse pairs in the U.S. were analyzed for degree of compatibility according to various social and biometric traits. These traits included lifestyle habits, education, physical attractiveness to the study subject, tendency toward extroversion and impulsivity, and religion, among others. Of all of these factors, political leanings ranked second only to church attendance as the primary selector.

So if in the wake of the election you are wondering how anyone could have supported LePage if you voted Michaud, or Michaud if you voted LePage, bear in mind that you may be engaging in the early stages of cross-species communication. The answer you seek may make no more sense than cats judging dogs and dogs judging cats. And if such cross-species conversations don’t happen at all, then we are more likely to continue to diverge as separate species.

Eben Rose lives in South Portland.