Neuropolitics.org

Scientists Discover a "Liberal Gene"

by Robert Haston
(Author of The Origin of Political Species)

In Friendships Moderate an Association between a Dopamine Gene Variant and Political Ideology Jaime E. Settle and 4 other scientists have discovered a link between longer repeat sequences of the DRD4 dopamine receptor gene (DRD4 7R) and political orientation.

As Brack has noted earlier, this gene has been related to both conservatism and liberalism. One reason may lie in our evolutionary past. A drive to expand may come from either "conservative" traditional territoriality (R strategy) or a new "liberal" (K strategy) adaptation. Starting 60,000 years ago, new technology such as watercraft and cold weather clothing, along with higher population density would have laid fertile ground for novelty seeking explorers. For this to be correct, such a gene would have evolved during this era and be highest among our ancestors who explored the furthest. The optimal form of such a behavior gene would make it respond to a stimulus, such as higher population density. Otherwise when the environment changed again to favor a more conservative approach, they would be left out in the cold.

We can see that this study correlates with all three. Obviously we weren't evolving genes for flip-flop liberalism 40,000 years before modern politics; modern politics just reflects the type of animals we came to be long ago. As you can see from the figure, the level of self reported liberalism isn't directly tied to the gene in question. It is only observed if the individuals had higher numbers of friends in adolescence.

The dark line indicates mean relationship while shaded areas indicate 95% confidence intervals

I look at this from the perspective that very little evolves and passes the test of time without a reason, and that all organisms evolve to be incredibly well suited to their physical and social environment. Maybe by evolutionary design, this is a stimulus-response instinct. In this case, organisms with the 7R genotype exposed to higher levels of peer contact respond by expressing traits more suited to larger groups.

Since our literal political instincts come from many genes, there won't be a single "liberal gene". But if further studies prove this out, they have found a major piece of the "Holy Grail" so to speak. To qualify, it would have to meet three criteria:

·        It would highly correlate with our main category of modern sociopolitical motivation (conservatism/liberalism)

·        It would evolve from an acknowledged environmental pressure (a transition towards larger and more complex societies)

·        To have a variation in our species it would have to have evolved either in different locations (which can be discounted) or during a period of profound and relatively recent transition. The period between 60,000 years ago and the dawn of modern civilization is far and away the most likely era.

Since the 7R allele arose roughly 40,000 years ago, this meets all three criteria. By their own definitions, conservatives see the world through an outward looking lens of self interest, while "we are the world" liberals turn this lens inside out and see the world from outside inward. Now consider that during the last 60,000 years, man evolved from small family troops to large tribes to giant empires. But these were turbulent times. Ice ages, multi-year droughts and other calamities swept the land, shattering these groups into smaller pieces.

So what would be better than a genetic adaptation to small conservative tribes or larger liberal ones? How about an adaptation to both! If you were only exposed to one or two playmates, you would tend to adopt a more conservative "focus on the family" view fitting the occasion. But if you were raised amongst the juvenile throngs one sees in a modern tribal village, you would lean more toward the view that "it takes a village". So rather than an adaptation to one change, this was an adaptation to change itself. Such an era would create the environmental pressure necessary to give rise to the "flip-flopper".

One such trait associated with 7R is novelty seeking. This would be a positive adaptation to higher population levels in prehistory. Seeking out new food sources (such as experimenting with fishing or agriculture) or new locations (Highest levels of 7R are found in South Americans) would be worth the risk as higher population levels stressed the local environment.

The authors were quick to point out that this wasn't a "liberal" gene directly tied to modern politics (a point that many people misunderstand). After all, how would something evolve 40,000 years before it was needed? Modern man has built up politics in his mind into a separate force of nature, as if it has its own modern physics, when its true roots lie in our ancient biology. In this light, one can see our political genes for what they are - the effects of a legacy of basic instincts that evolved from thousands to millions of years ago, but still shape the foundations of our behavior in this modern age. I remind skeptics that we don't have genes for immigration reform, but we do have genes for territoriality. We don't have genes for attitudes about gay rights or abortion, but we do have genes for fertility. Recent twin studies confirmed that attitudes about these are heritable. This is no surprise considering conservatives have 41% more children.

Here is how the authors put it:

Our common ancestors would have received little evolutionary benefit from a gene that bequeathed them with a liberal ideology. We do not suggest that DRD4 in any way evolved as a "liberal" gene. However, a combination of findings has led scholars to believe that the 7R allele did have some evolutionary benefit at an earlier time in human history. The DRD4 gene shows significant variation in human populations; the 4R allele is the most frequent, but frequencies vary greatly across different populations (Ding et al. 2002, Chang et al. 1996). Studies suggest that the origin of the shorter alleles can be explained by simple one-step recombination or mutation events, but that the 7R allele is "younger," originating approximately 40,000 years ago perhaps as a rare mutational event that increased to high frequency in the human population because of positive selection (Ding et al. 2002). Wang et al. (2004) confirm that the pattern of recombination is that expected for selection acting at the 7R VNTR itself, rather than at an adjacent site.

Ding et al. (2002) argue that the appearance of new technology and/or the development of agriculture could be related to the increase in DRD4-7R allele frequency. Novelty-seeking in this era could have been associated with reproductive success if carriers of the 7R allele were able to more easily adapt to changing environmental and societal conditions. Selection could have acted against those who were averse to change and experimentation. Furthermore, those with the 7R allele may have been more likely to migrate, leading to the wide dispersion of the allele across ethnic groups and the high prevalence of the allele in groups, such as those in South America, located long distances away from the site of human origins (Ding et al. 2002, Harpending and Cochran 2002).

We no longer face the same environmental challenges that our ancestors did, and it is argued that the presence of many alleles in our genome is a legacy to the benefit we accrued from it in the past (Gangestad and Simpson 2007; Barkow Cosmides, and Tooby 1992; Tooby and Cosmides 1990). When considering the contribution of specific genes to political and other social behaviors, it is important to keep this evolutionary perspective in focus. Population genetics do not evolve as rapidly as society, and thus the genes we inherit influence our response to modern situations, even if those genes have survived and propagated for very different reasons. The long alleles of the DRD4 gene may have helped our ancestors explore and innovate in the environment they faced 40,000 years ago, separating novelty-seekers from their more generally unadventurous peers. Today, those same alleles may indirectly contribute to political ideology as a legacy of the adaptations of our past (Corning 2004; Tooby and Cosmides 1992).

Robert Haston, January 2009

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