From the moment we’re born until the day we die we find that our behaviour affects those around us, but what drives our behaviour? Are we totally in control or are there influences at work which transcend our conscious involvement? You’ve likely heard that humans generally seek pleasure and avoid pain. There’s a very good neuro-physiological reason for this. The brain contains a circuit known as the incentive and reward pathway which is located deep beneath the cerebrum. This is where we process many felt-sense experiences such as the enjoyment of a tasty meal, a good glass of wine, the thrill of a loving touch and the beauty of a sunset. Because these things are enjoyable we seek them out either consciously or unconsciously. They drive our everyday behaviours on a very deep level. These motivations could be described as selfish, but we also enjoy being unselfish – as the adage goes, “it is better to give than to receive”. The limbic system is very sly and full of guile. Its primary goals are the survival of the individual and to reward key behaviours. It also contains the seeds of its own demise.
In the 1950’s, Abraham Maslow identified a set of primary motivations that are shared by all humans which he referred to as needs. Many researches have explored this space and some have used the word “wants” instead of needs. I overheard a conversation on the beach that helps illustrate the distinction. A child wanted a shovel his sister was using to build a sand castle. There was only one, and this scarcity introduced some tension into the situation. The little boy repeatedly stated, “I want it”, then when it seemed there would be no response from his mother he said with an indignant tone “I need it”. Did he need the shovel or want it?
Our culture associates wanting something with a selfish desire for an object that is not necessary, whereas to need something is more of an imperative, but this is not necessarily the case if needs are viewed through Maslow’s lens. His hierarchy of needs begins at the lowest level with a set of physical inputs that the human body requires in order to survive. These include food, water and air. A human can exist without air for a few minutes, without water for a few days and without food for a few weeks but after those respective periods of time the result is always the same – death. These inputs can surely be called needs as we need them to survive. The next level of the hierarchy includes safety and security. Here things are a little less clear. We can survive without safety for a long time, but the chances of survival are lower. If we live in an environment full of predatory animals there is a higher probability that our life will be taken early, but many people in such an environment live to a good age. My grandfather fought in the Battle of the Somme in World War I, but lived until he was 80 years old. Survival at this level is no longer contingent on absolutes but rather probabilities.
Do we want security or need it? The child on the beach could have built a sand castle with his bare hands, but this would have taken longer than by using the spade. He needed the spade to complete his task with a measure of ease. In the same way security provides a level of ease that forms the foundation for contentment. Without the risk of attack by wild animals there is no need to set a watch or build secure accommodations. The next level of the hierarchy involves belongingness and love needs. It’s clear that the child on the beach would see the gifting of the spade as a sign that his mother loved him and that withholding it would introduce doubts about that. There is also the issue of sibling rivalry and how important the boy felt in the family context. This state of affairs is at Maslow’s level of esteem needs. All of these non-essential factors could be described as wants, but if viewed as pre-requisites for a particular goal they become needs. If the ceilings in our house are 12 feet high we would need a ladder to change the light bulb. It’s not that we need a ladder for survival, the human race survived for millennia before the ladder was invented, but a ladder is required to reach the goal of a newly installed light bulb. In the same way, if the goal is to feel loved there are certain prerequisites that are needed to reach that goal.
I want to emphasise the word “feel” in the previous sentence. This word places the experience firmly in the incentive/reward pathway. How important are feelings? This is a judgment that depends largely on how empathic your culture is, and this in turn depends on the social conditioning of its citizens. During World War II my father was a teenager and times were hard in the UK. People were subjected to rationing, air raids and a continual state of fear. Families were being destroyed and children orphaned. It was popular at the time to follow a process of “hardening off” with your children. Parents were expected to toughening them up by withdrawing emotional connection, softness and kindness. It was thought that this would give them the tools to cope if their parents were taken from them in one way or another. Feelings were not regarded as very important at that time and the overall principles were “Keep calm and carry on” and “big boys don’t cry”. Feelings were not very important in most cultures until the late 20th century, especially in the nations of the Soviet Union. Things have changed a lot over the past few decades and now being able to appreciate not only your own feelings but also the feelings of others is seen as a necessary pre-requisite to avoiding conflicts of all kinds.
So what is the role of dopamine in all of this. Let me illustrate using an analogy. I was speaking recently with a financial advisor concerning my mutual fund portfolio and happened to ask him “how does the performance of my investments relate to the Dow Jones Index?” He responded “Ah well, everything usually comes down to that in one way or other”. Dopamine plays a similar role in regulating behaviour to that played by the Dow Jones Index in the field of stock performance. There is only one incentive/reward pathway and a central component of this is the nucleus accumbens. This is where we experience the incentive to take action, and the incentive is created by the expectation of reward. The reward is experienced as a good feeling be it a sense of accomplishment, satisfaction, flavour, freedom or pleasure. When we anticipate a reward the dopamine levels in our limbic system spike. We take an action and the dopamine levels rise again to provide the rewarding sensation. The sensation of reward is multi-faceted. It involves dopamine for its expression, but the subjective experience of the reward can take many forms.
Think of the nucleus accumbens as a light bulb that can display any colour imaginable. We might experience one rewarding sensation from smelling Chanel Number 5, another when watching a Lamborghini drive by, a third while listening to our favourite song and a fourth from taking a bite of our favourite cheese. These sensations all take place in the limbic system, as electrical signals are propagated in myriad ways depending on the stimulus and our memory associations with that stimulus. The term often used to describe this is a “lighting up” of that part of the brain on a brain scan, most commonly a Positron Emission Tomography (PET) or Functional Magnetic Resonance Imaging (FMRI) scan.
PET scans show the distribution of a particular radioactive marker drug as it binds with a target receptor. FMRI scans show which parts of the brain are active based on blood flow. In both these cases the view of the brain is essentially monochrome. The level of activity can be colour coded, but this is a false colour view that has little relation to the subjective experience of the activity. I’m using colour as a metaphor for what the subject is feeling. We walk out of our house on an early spring day and smell the freshly cut grass. This might light our limbic system up one colour as we feel a sense of possibility, of hope for the arrival of warm weather. If we’re allergic to freshly cut grass the chances are it won’t light up at all…or light up in a way that indicates aversion. We walk past the window of a department store and see a gorgeous dress in the display, our limbic system lights up another colour. It’s a rewarding feeling that is totally different from the previous one but it’s still a result of the flash of electrical activity. Someone else might walk past the same display and find the dress unappealing.