There is substantial evidence that Americans are becoming more conservative. In our June 2005 survey, 76% of the Conservatives and 7% of the Liberals say they have become more conservative. In contrast, 65% of the Liberals and only 2% of the Conservatives report becoming more liberal.
The theories that account for this phenomenon are typically informal and have been piling up quickly. We have a recent neo-Darwinistic theory that proposes that the different reproductive rates of conservatives and liberals is swinging the population towards conservatism. This is informally referred to as the Baby Gap Theory,
This theory proposes that conservatism and high birth rates are mutually reinforcing, at least among caucasians. According to this theory, the conservative philosophies of anti-abortionism and pro-heterosexuality naturally lead to higher birth rates. Bush carried the 19 states highest in white fertility. Kerry won the 16 states lowest in white fertility. Are white Liberals being gradually eliminated by natural selection?
To make matters worse for the Liberals, our most recent survey found that Conservatives are 21% more likely to carry on the political affiliations of their parents. Higher birth rates and higher rates of political heredity make for a significant advantage for the Conservatives over time.
Below, we see a blue and red map of the continental United States. The blue states indicate a victory for Kerry, and the red states indicate a victory for Bush.
2004 Presidential Election: Bush (Red) vs. Kerry (Blue)Interesting is the close proximity of the blue states to major bodies of water in latitudes generally above 36 degrees. Of the 19 states that voted for Kerry, 18 of them border major bodies of water (Pacific Ocean, Atlantic Ocean, and the Great Lakes). Vermont is the exception, but is still very close to the Atlantic.
California is a special case due to its wide range of latitudes---it extends from 32 to 42 degrees. However, in the southern portion of California, the caucasians tend to vote conservatively. San Francisco is at 37 degrees, and slightly above the lowest latitude where we find any counties in California where caucasians preferred Kerry.
Another anomaly is Hawaii, which extends between 16 and 23 degrees north latitude. where 58% of Caucasians preferred Kerry compared to 42% for Bush. Caucasians make up about 22% of the Hawaiian population.
Alaska is another anomaly, with a lower latitude of 51 degrees and an upper latitude of 80 degrees. However, the unusually low population density makes it a special case. (See our upcoming discussion of the relationship between population density and political affiliation in our next issue of Neuropolitics.org).
Caucasian skin is not well adapted to handle the levels of sunshine that are generated in the latitudes near the equator, and for the most part, the caucasian diaspora from Europe would reflect a preference for latitudes between 20 and 55 degrees, in both hemispheres, with the exception of ocean-cooled equatorial regions.
The lowest latitude of mainland Europe, where the caucasians originated, is about 36 degrees. If we look at precipitation patterns of the states above 36 degrees, we see a positive correlation between liberal voting and rainfall.
Let's take a look at the county by county voting patterns for the 2004 Presidential election for the state of Washington:
County Map: 2004 Presidential ElectionBlue indicates a stonger preference for Kerry, and Red indicates a stronger preference for Bush. White is about even. Note that the western and more highly populated areas of Washington indicate a higher preference for Kerry. Now let's look at the precipitation map for Washington:
Precipitation Map: WashingtonThe green and blue areas indicate higher precipitation rates, and the other colors represent lower. This correlation between precipitation and caucasian voting patterns is not isolated to Washington. Precipitation is correlated with voting trends in many states.
This correlation between precipitation and caucasian liberalism is common in latitudes above 36 degrees in regions with higher population densities. This is circumstantial, but there are some good reasons for believing that differential exposure to sunlight is having at least a partial impact on our political preferences. Note that higher population density also reduces exposure to sunlight, as we will discuss in our next issue of Neuropolitics.org.
Caucasians have reduced cutaneous melanin that is well adapted to the reduced sunlight of the higher latitudes of the European subcontinent. When sunlight hits the skin and the retina, it drives a biochemical chain of events that has some similarities to photosynthesis in plants.
Sunlight is important because it contains three kinds of light: infrared, visible, and ultraviolet. Infrared light provides heat, but visible and ultraviolet light can cause structural changes to a variety of molecules that are required in biochemical reactions. The intensity and duration of sunlight exposure is proportionate to the synthesis rates of these molecules.
Sunlight exposure has a dramatic impact on testosterone production in males, as plasma testosterone levels decline from November through April, and then rise steadily through the spring and summer until peaking in October. This directly impacts reproductive rates, as the month of June has the highest rate of conception.
Those living in lower latitudes with generally lower precipitation rates have a year-round advantage in testosterone levels and the corresponding increase in sperm production. Indeed, the caucasian movement from Europe into lower latitudes was followed by higher birth rates, which were partly due to the sunlight-induced testosterone levels.
The general tendency for males to be more conservative than females surely implicates the role of testosterone, with its masculinization of the human body, and in particular the brain. There is evidence of a variety of structural differences in the corpus callosum and the anterior commissure between males and females, along with generally more asymmetric functionality in male brain, and testosterone is the primary suspect.
But there is also recent evidence of a testosterone-dopamine link, as Hull et al (2004) have found that testosterone ultimately increases basal dopamine release in males. Dopamine has been implicated by Tucker and Williamson in 1984 to be asymmetrically distributed in the left hemisphere, and Conservatives, in general, tend to favor left-hemisphere cognitive styles.
This could explain the male movement towards conservatism, but in our most recent survey, females are becoming conservative at a faster rate. But there is a corresponding explanation with females, and it involves the hormonal counterpart of testosterone---estrogen. Estrogen varies naturally within the menstrual cycle, and also varies proportionately with sunlight exposure. Sunlight assists in the dual role of masculinizing men and feminizing women. There is also substantial evidence of an estrogen-dopamine link, so the female is subjected to a similiar hormonally-induced dopaminergic influence.
But a Sunlight Exposure Theory of Political Preference explains the correlation between birth rates and sunlight exposure via increased testosterone and estrogen levels. That same elevation in testosterone and estrogen also promotes the release of dopamine, and the left-hemisphere is organized around a dopaminergic activation system. Conservatives in general exhibit more left-hemisphere cognitive styles than do Liberals. Sunlight's concurrent priming of the sex hormones and the left hemisphere's dopaminergic activation system could explain the elevated birth rates and the relative scarcity of caucasian liberalism beneath the 36 parallel, especially in the areas with higher average sunlight intensity.
Brack and Zhang, August 2005.
