There is a human gene called DRD4. A mutation in the DRD4 gene can give ADHD (Attention Deficit Hyper Activity) to the people who have the mutation. People who have ADHD have difficulty with controlling their impulse. Many of them marry young, have early pregnancy, have many kids, etc. In all, there is every reason to expect the DRD4 mutation (and ADHD) is going to increase in the human population.
ADHD, of course, can pre-dispose a person to several setbacks. Learning difficulty is the most well known affliction of ADHD. People with ADHD are more vulnerable to addictive behavior, temper outbursts, poor job performance, etc. About 65% of the inmates in Western prisons suffer from ADHD spectrum disorders.
DRD4 is clearly behaving in a way that is detrimental to the carrier animals. But the same behavior is helping the gene to maximize the number of its own copies in the population.
Genes behave in a way that increases the number of its copies. Over time, any gene that doesn’t doesn’t toe the line gets ‘subsumed’ by other aggressive genes. Because our language lacks adequate words to describe such behavior, we talk as if the genes are people (anthropomorphic thinking) and claim that the gene is behaving selfishly and we call such a gene a selfish gene. Obviously, the gene is not people and it doesn’t think or act. More importantly, genes don’t have any objective or motive. They are mindless.
While the genes always act in a purest self-serving way (or they perish), sometimes their behavior is counter intuitive. Altruism is one such paradox. An altruistic animal seem to be an evolutionary dead end. But among pack/herd animals, taking care of one another had increased the chances of all the animals in the pace/herd. Over time, only the animals with altruistic genes were alive and the rest perished. While altruism appears self-less, it is in reality promoted by a gene acting in pure selfish fashion.
But when an animal feels altruistic, the feeling of altruism is very real. Even though the altruism is a product of a selfish gene, that is a mere technicality. It is like saying “oxytocin release in your brain makes a mother bond with her child”. Of course it is true. But the technicality doesn’t make the mother-child bonding any less real.
We often confuse the selfish motives of our genes with the motives an the animal. We shouldn’t. We are not our genes. We are not more. We are not less either. We are different.