"I am firm; you are obstinate; he is a pigheaded fool."*

German geneticists believe that they may have discovered the "gene" for stubbornness. It turns out that those of you who stick to your mistaken beliefs in the face of all evidence may suffer from a shortage of one kind of dopamine receptor. Perhaps this explains President Bush and certain Hit & Run commenters? (We all know who you are.) In any case, Earthtimes reports:

People who are stubborn and never seem to learn from their mistakes may have a mutated gene that makes them bull-headed, according to scientists in Germany. About one-third of the population have this mutation, which may be nature's way of ensuring that there are always some people who will not give up trying when at first they do not succeed, say the researchers at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany. …

The A1 mutation, the researchers say, leaves people with fewer D2 receptors in the brain that are activated when levels of the neurotransmitter dopamine drop. Dopamine is not only responsible for signalling fun and pleasure in the brain, but the neurotransmitter also helps in learning.

Klein and Ullsperger theorise that the lower output of dopamine means that some people simply are not satisfied when a decision or action turns out to be a mistake. So they repeat their mistakes. People with more D2 receptors in their brains are satisfied the first time around that a mistake is a mistake. They do not feel any desire to repeat it.

Link to Earthtimes article here.

*Headline explanation here.