Why do we dream?

February 20, 2009

Some people claim that our dreams are the manifestations of our subconscious, i.e. the brain’s way of telling us what we “really want”. However, I see no logical reasoning behind this claim. In reality, I think it mimics the same way of thinking that leads to religion, astrology, new-age “medicine”, and the likes – human beings like to “personify” things. This claim is explained in Richard Dawkin’s book, the God Delusion.

When giving our dreams meaning, we personify our brain, giving it a separate entity from our own, believing that it somehow “guides” us in our life, bestowing on us its “mystic” wisdom. It is a comforting thought, since it provides us with hope that there is a bigger plan, or that we have a guiding force in our life, a guardian angel if you will, that watches over us and guides us. I see it as a romantic idea, wishful thinking. A human need.

However, scientific doctrine aims to remove humans from the equation, reaching conclusions which do not rely on the human observer. Therefore, if there is no logical explanation for this subconscious, which (or maybe I should say “who”?) tells us what we should do with our life, but only through dreams that we need to interpret using unscientific methods, i.e. intuition, I must look for an explanation which relies on known scientific axioms.

An axiom which immediately comes to mind is evolution.


I will not go into the whole evolution vs. intelligent design debate, since you can find plenty of websites which discuss it, and since frankly I could just as well debate evolution vs. the Flying Spaghetti Monster.

If you “believe” in evolution, and more importantly, if you understand it, you realize that each living organism on this planet looks the way it is today since, quite simply, all the other ways were not good enough. In other words – its current state is dictated by whichever changes that allowed it to survive better. This survival is not an inner mechanism or something that drives it. There is no “force” which makes evolution exist. Things which are best suited to survive do just that because they are best fitted to do so. Kind of recursive πŸ™‚

So let us go back to the title of this blog entry – “Why do we dream?


I offer an evolutionary point of view, combined with computer science thinking.

The human brain is composed of connections. The more we think in a certain way, the more certain connections become stronger, reinforced. That is why astronauts undergo extensive underwater training before going on missions. It takes time for the human brain to adjust to new points of reference in space. Astronauts in microgravity usually lose their sense of direction and feel uncoordinated or clumsy. Because inner ear and muscular sensors seek terrestrial clues, astronauts must learn to rely on visual cues for balance and orientation. But even visual cues can be confusing – astronauts in microgravity need to adjust to the fact that up and down don’t really matter in space like they do on Earth. They need to “force” their brain to think differently, and that takes time.

The same goes for human emotions. If for example you are a person who is always depressed, you will not be able to change overnight. Changing your way of thinking and behaving will take time, since you are “re-wiring” your brain (however, if you want a “quick fix”, you can always get a brain pacemaker transplant – http://en.wikipedia.org/wiki/Brain_pacemaker). The more you think differently, the more these connections become stronger, and the other become weaker. It is a very elegant code if you think about it from a programming point of view. It makes itself more efficient and streamlined, according to the relevant needs. Human emotions might not relate to evolution so clearly, but if we consider other brain functions such as moving about, breathing, or recognizing a lion in the bushes – it is vital for our survival that we carry out these actions successfully and as quickly as possible. Our brain has evolved in a manner which makes sure that whatever we do the most – i.e. whatever we need to do to survive more, we do as efficiently as possible. Assuming of course that whatever it is that we do the most is beneficial for our survival – perhaps not so true in the 21st century (for instance, I don’t think that reading this article improves your chances for survival, although I’ll be flattered if you think so), but most definitely true in most of our evolution, which took place in the wild, in much more harsh conditions.



So the connections in our brain constantly grow stronger in various ways, according to what we do and how we think. It has been known for quite some time that the augmentation of these connections mostly happens when we sleep, as corroborated by a recent study (http://www.eurekalert.org/pub_releases/2008-01/uow-sbc011808.php). This is known as plasticity (http://en.wikipedia.org/wiki/Neuroplasticity). It also makes sense – as every person with a computer knows – it isn’t very smart to install/uninstall computer programs while they are running.

So why do we dream? Well, my hypothesis is that our dreams are a “system-check” carried out by our brain. When you go to sleep, your brain shifts synapses in your brain, making some connections stronger, some weaker and perhaps even creating new connections or completely severing old ones. After making each change – it is a good idea to run a system-check, don’t you think? That is also why our dreams seem so real. As far as we are concerned, the messages in our brain when we dream are identical to the ones we get when we are awake – or else it wouldn’t be a very good systems-check, now would it? Also, that is why dreams relate to memories – that is the information the brain has available to use for its systems-check. Furthermore – dreams usually relate to recent events, since those are usually the areas which get modified.

But the most important part in my hypothesis is why I think my argument is true. After all, I can find lots of explanations for why we sleep, why is mine more logical than the rest? Well, I suggest that this systems-check is a direct result of evolution.

Consider that our brain evolved, and we started making more and more connections. Obviously, these connections were augmented in our sleep, since if you started making changes in your brain while you are awake and running away from a cheetah – well, let’s just say your survival chances were not very good.

But some individuals also started having dreams. Those dreams were the systems-check carried out by their brain, making sure that all of these new connections were OK.

So those who had dreams one-upped their fellow tribe-members evolutionary-wise. They had less chance of suffering the consequences of “faulty-wiring”. And we all know how one bug in a program can wreak havoc…