Short Serotonin Transporter Gene Makes People Risk Averse
It helps to have a long serotonin transporter gene if you want to find the will to take a big financial risk.
People with the short serotonin transporter gene, 5-HTTLPR (two copies of the short allele), relative to those with the long version of that polymorphism (at least one copy of the long allele), invested 28 percent less in a risky investment. Similarly, people who carry the 7-repeat allele of the DRD4 gene in the dopamine family, relative to those carrying other versions of that gene, invested about 25 percent more in a risky investment.
"Our research pinpoints, for the first time, the roles that specific variants of the serotonin transporter gene and the dopamine receptor gene, play in predicting whether people are more or less likely to take financial risks," said Camelia M. Kuhnen, assistant professor of finance, Kellogg School of Management at Northwestern. "It shows that individual variability in our genetic makeup effects economic behavior."
"Genetic Determinants of Financial Risk Taking will be published online Wednesday, Feb. 11, by the open-access journal PLoS ONE. The study's co-investigators are Kuhnen and Joan Y. Chiao, assistant professor of psychology at Northwestern.
Prior research linking the two genetic variants of 5-HTTLPR and DRD4 to, respectively, negative emotion and addiction behaviors suggested to the Northwestern researchers that those particular brain mechanisms could play a role in financial risk-taking. But until the Northwestern study, the identification of specific genes underlying financial-risk preferences remained elusive.
When people gain the ability to choose genes for their offspring will they opt for a shorter or longer version of this gene? How will future humans differ from present humans genetically?
I don't see any major advantages for either temperament. A person who is overly aggressive loses. A person who isn't aggressive enough also loses. And in the real world, knowing the optimal level of aggression is a non-trivial problem.
Parents who are sophisticated enough to want to alter the risk tolerance of their children might go for a mixed strategy, half high and half low. If that is the case, my guess it that they would opt for males with higher risk tolerance and females with lower risk tolerance.
There is no optimum human personality.
Human's did not evolve to function as individuals, we evolved to function as team members. It is the team that is the final decision making entity. Inside the team you have risk taking and risk avoiding personalities. The conflict between the two steers the team to an optimal solution.
All of our personality traits fall upon a spectrum for this reason. It creates a team/society with multiple perspectives on each collective problem. In extreme cases, the risk taking indiviudals can risk themselves while the risk averse hang back. If the risk takers succeed, the team benefits, if they fail, the risk adverse remain to carry on. This is a long term multi-generational genetic strategy.
The problem with genetic engineering is that most people to intuitively feel that there is a perfect human personality and will try to engineer it thus creating population comprised of personalities of one pole or the other. The resulting society will be either to prone to take risk or to risk adverse. The solution is to develop a broader understanding of how our behaviors fit into the bigger picture.