Now we've all been in that situation where you have the choice between doing something fun but bad in the long run and doing something boring but will do you good in the future. As a student I am acutely aware of this problem- I should probably be doing something more relevant to my work right now, but oh well.
That "oh well" phenomenon is what I'm going to try and explain here. Why do we forsake long term gains for short term bursts of reward? Well it turns out that there is a very logical explanation, and if you know how this system works, you can effectively trick yourself into being more forward thinking and making decisions that will help you in the long term.
There are 2 competing systems at work here. The first is the more primitive instant gratification/ reward system that uses primarily the neurotransmitter (brain chemical) dopamine and is based more centrally in the brain- which is also involved in schizophrenia and Parkinson's disease (motor function). In this system, dopamine receptors are activated more often, due to an increase in dopamine release, which results in a rewarding or elated feeling, in a dose-dependant manner ie the more dopamine receptor activation, the more reward you feel. The second is the more recently evolved long term planning and decision making system, which uses many neurotransmitters and is based in the front of the brain- particularly in the prefrontal cortex. Some of you may remember this area from a previous post about why your 20's are the most important years of your life, and how this region only really fully develops during your 20's. These 2 systems compete with each other in your unconscious brain for the most part, and they normally come to some sort of compromise- like "I'll do some work and then I can binge on *insert tv show here*". The problem is however, that this is not an even playing field and it is very easy to succumb to the temptations of instant gratification. This is because these short term feelings of reward give much greater highs of emotion. Think about it, what's the biggest emotional reward you get when you do something good for you long term? Maybe a smile breaks out and you give yourself a pat on the back? Then think of the biggest emotional reward you get when you do something really indulgent, like eating a whole chocolate cake, or sacking off lectures to enjoy the Sun- that ecstasy of just saying "f*ck it" and doing whatever you want is SO much more fulfilling than not doing it, which makes it very hard to resist the temptation and is why so many of us do things we know we really shouldn't.
You might wonder why this dopamine system even exists, in modern day life it appears very counter-productive. But then you have to realise that, deep down, we are still focussed on 2 things, survival and reproduction. Everything else is just an accessory to those 2 core needs that all of us have. The euphoric highs of surviving a near death experience or that grin you have on your face after amazing sex are a million times better than the feeling you get when you set up a pension or when you've worked on your coursework. This dopamine system is so powerful that people are extremely motivated to do anything that triggers it ie people are highly motivated to survive and reproduce, meaning that they will do almost anything to ensure that these things happen. What's bad is when this system becomes misdirected, and you find yourself more motivated to do things that are bad for you long term. Normally, this is evened out by the prefrontal cortex, which suppresses these urges often enough, so an occasional indulgence is not a problem, however this is not always the case.
This is exactly what happens in addiction; more and more addictions are being related to the dopamine reward system than I can keep track of, so for the sake of ease I'm going to assume that all addiction is mediated by this system. This means that the dopamine system overruns the prefrontal cortex so much that people will forsake even the key needs for survival (food, water, sleep, shelter) and even sex in order to keep up these dopamine highs. The most obvious addictive behaviour that is caused by the dopamine reward system is Cocaine. Cocaine binds to and activates dopamine receptors in the brain, which triggers the reward system and makes you more likely to take Cocaine again next time the opportunity arises, eventually resulting in a craving for this reward and active search to obtain more Cocaine, at the expense of health and well-being. In essence, anything rewarding can become addictive- and you just have to Google "addicted to" to see just how many weird things people can be addicted to (my personal favourite weird addiction is eating dry wall, which affects a worryingly large amount of people). So in essence, the dopamine reward system is an essential part of our very existence (personally I feel very good when I don't die) but only as part of a well balanced system. When left unchecked, it can run riot with your motivation and potentially ruin your life.
This goes some way to explain why children can be so impulsive and why many teenagers make very bad decisions eg getting pregnant, starting smoking, getting involved in crime without really realising the impact that these decisions will have on their life in the future, because the prefrontal cortex is not yet fully developed, and so they are more susceptible to the powers of temptation by the reward system. This also goes some way to explain why many people that suffer from ADHD and the like can often "grow out" of their conditions. Sticking with ADHD, many drug treatments for this condition utilise the dopamine reward pathway in order to relieve some of the behavioural symptoms they may exhibit. Essentially ADHD sufferers are extremely impulsive and almost always take the immediate reward over the delayed reward, even if the delayed reward is greater than the immediate.
This constant need for reward often makes them disruptive, so a number of drugs target the dopamine system in order to remove this reward craving. Methylphenidate (more commonly known as Ritalin) is the most common example of this, it is a dopamine reuptake inhibitor. This means that, instead of dopamine being retaken up and recycled (as is the case for all neurotransmitters- otherwise every receptor in our brains would be activated at once and we'd never do anything) it stays in the synapse (the gap between neurones) and is able to activate dopamine receptors a while longer. This gives the ADHD sufferer a much needed boost in feeling of reward, and eases their craving for immediate rewards. This is not too dissimilar to from the many tribes that have found that they can stay alert and motivated for much longer if they chew the coca leaf- from which cocaine is derived.
Essentially, they get a slight but prolonged increase in dopamine receptor activation which results in a mild sense of motivation and contentment, allowing them to work long hours on their feet during the day. In fact, not only tribes people have cottoned onto this- many military personnel chew coca leaves to stay alert during conflicts. The reason many of these people can live a normal, healthy life while consuming cocaine on a regular basis, is because the effect of the drug is dose-dependant. The small, prolonged reward from chewing the coca leaf is not really going to having any effect on the attitude towards the drug. however the massive short term hit of euphoria from cocaine can have a very profound effect on behaviour and change a persons attitude towards the drug massively.
This can be applied to our everyday lives, you can begin to see how behaviours can be seen as hits of dopamine, with good and productive behaviours giving a long, low level of reward and bad behaviours giving a short but big level of reward. So now we've come full circle, a little bit of dopamine is good, a lot of dopamine is bad; just try to get the right balance :)