Intoxication, Addiction and the birth of Addiction

Foreward (written after the post): This article is very vague in what it tries to explain - the evolutionary insight into addiction. It actually relies on evolutionary theory.

This post is a little about what happens in the brain when we get intoxicated or addicted to a substance. I suppose this post will highlight a little about the neurobiology of the brain. I don’t consider everyone to be an addict in any way; but I believe people are more susceptible to be a victim of addiction in general. The only way to understand ‘why this is so’ is to understand the biochemistry of the brain, and a little evolutionary history about it. Before I move on, I just want to clarify the two terms – intoxication and addiction:

Intoxication is the state of being affected by psychoactive drugs. It may also refer to the effects of consuming poison or excess amounts of harmless substances. Since I am not talking about intoxicating substances which are lethal or cause instant death I am ruling out the second definition. Intoxication may result in relative euphoria, feeling of pleasantness, etc. These are common symptoms. However not everyone experiences the same symptoms the same way. For some the relative euphoria is a sign of panic, and hence they develop a hate toward these substances. However the general trend is that people rather enjoy the feeling. Addiction is the next level of intoxication. It is much more serious. It is the physical dependence on a psychoactive substance which, when suddenly stopped, causes what is known as withdrawal symptoms. Some common withdrawal symptoms are anger, lethargy, depression, anxiety, etc.

Brain Evolution
Sometimes our brain can be considered to be a huge response system. It responds to various stimuli. And to get these signals or messages across to various regions for processing, the brain relies on its intricate mesh of neurons and neural network. There are some signals that can trigger panic, or readiness to attack, etc. These particular signals are ‘wired’ for the primary reason of survival. We perceive panic or the readiness to attack through a phenomenon called emotion. Neurologically, this is how we would behave when there are certain levels of chemicals (neuro-transmitters) present, taking a particular emotional phenomenon in context; for e.g. when feeling sad or suffering from anxiety, we can observe high amounts of a neurotransmitter called serotonin. (Serotonin has other function like regulating sleep, the cardio-vascular system, etc).

There are two kinds of emotion – positive emotion and negative emotion. Positive emotion works in a scenario where the brain (or the organ called the brain) has realized that there is something positive. For e.g. edible fruits on a tree. If we come to know that we are able to eat fruits from a tree, and that they are abundant, we would naturally be happy. This is a positive emotion which would make us want to consume more fruits from that tree. You can derive a corresponding case for a negative emotion too. Hence as a conclusion you can say that the brain seeks positive or rewarding scenarios most of the time for the simple reason called survival.

The reward system
Now that you know that the brain seeks for positive signals, you should also know that there exists neural pathways or channels and/or reactions which would generally come under the an umbrella the reward circuitry system. In the days of prehistory, the reward system in humans was relatively undeveloped. Perhaps early humans who primarily relied on hunting/gathering for survival did not require one. They were not exposed to intoxicating substances like modern humans. Reward for them was being a successful hunter and acquiring lots of food. Or being reproductively successful, etc. But as food became scarce they became physically unfit for hunting; they discovered that these intoxicating substances could boost their hunting stamina, or even sometimes their reproductive success. However, these substances were not administered in amounts that would cause chronic addiction.

As we became more civilized and started to settle our urge to hunt and feel superior etc, still remained. These programs were still running inside their brains. And consuming intoxicating substances was the only way out. Thus we see the evolutionary birth of addiction.

Monogamy Demystified

My previous post would form the proper context for this post, however for the googlers and other curious people who ended up here, the question I am trying to answer is simply:

...why monogamy?

Our ancestors (the evolutionary one, not social one) were primates. Primates, even today indulge in polygamy. Hence its not surprising if I told you polygamy is practised in some human cultures in one form or the other. So this means polygamy was a good part of our evolution. 

Then why is it not as popular today like it was before...?

Right now I believe monogamy is more of a social construct rather than pure natural evolution. In other words I say it is social evolution. It kind of forms the basis for humans to be able to live in a society. There could have been a time, in the nomadic or in the agrarian days, where the males actually decided to invest in reproduction.

Investing is good thing for the offspring. There is more guarantee that the offspring can reach adulthood; by then he or she would have also learned necessary skills to go about life. The group of people had an idea of the skills they needed to impart to the next generation. So on one part it was about training the generation.

There was another socio-evolutionary aspect of this kind of investment. It was that the group needed more of these trained generation to advance their society. Indirectly, we can conclude that the law of survival is still obeyed. And so is the gene expansion program being obeyed in a restricted sense. These two factors could have led to the group's survival.

The males didn't have to fight wars over trying to possess a female anymore. This meant fewer injuries. Plus, their investment into parenting, training the child, etc play an important process in social evolution.

From the reasons I've stated here I believe monogamy is about being able to live in a society. Monogamy gets all the advantage of a nuclear family too. But one should not think that monogamy was the definite reason why the society is a lot stable today than erstwhile. In fact we have no proof that monogamy really leads to a stable peaceful society. But considering the graph so far I think this is what it appears to “be”. But don't be deceived.

But we still see violence happening in society due to many reasons. Tensions of war, crime, etc all plague society. Monogamy has done its part, and is probably still doing it. These problems are rather lack of resources to counter the rising human population. Imagine those little fights we had over a territory or a person, or on anything you are very much dependent on. The only difference is that they are now on mass scale.

Update (12th Sep 2013) : added some bundles about monogamy - http://bitly.com/bundles/deostroll/w