Evolution is slow. Really slow. Not like the ‘Haggunenons’ in Douglas Adams’ Hitch-hikers’ Guide to the Galaxy who evolve from one moment to the next. It is iterative, gradual and random.
Intelligence allows us to outwit evolution. It gives us the ability to adapt our behaviour and so advance more quickly. Not in a physical sense – unfortunately, we can’t actually digest rocks or pull oxygen from water through our skin so we can swim endlessly underwater. But we can, and do, extract nutrients from the earth to supplement our diet and we are able to carry oxygen underwater with us in tanks. Now, we can even use mechanisms to extract oxygen directly from the water while we swim.
The brain uses around 20% of the body’s power, the highest consuming organ we possess
Our brains are the result of millions of years’ development and are extremely expensive from an energy perspective. They use around 20% of the body’s power, the highest consuming organ we possess. But the benefits that come from working things out far outweighs this expense. To supply our bodies and the power-hungry resource that drives it, we seek out high energy, high calorie sources of food. It is to our evolutionary advantage to do so. We have become biological slaves to our energy hungry brains. Lately though, we’ve used our intelligence to develop ways to produce high quality, nutritious food more easily and most of us don’t even need to go running after a gazelle to make sure we get a meal for our family. We can just go to the supermarket and pick one up. However, evolution being so slow to change, we are still driven by the same desires that served us well for hundreds of thousands of years.
We feel pleasure when we eat high energy foods because a part deep in our brains rewards us for having found an energy rich food source. It releases feel-good chemicals so we will do it again. Trouble is, it has no idea how much it needs. There will never come a time when it thinks “mmm that’s probably enough, I wont reward you for finding any more for a while” — you will always be rewarded.
Understanding why we feel these drives for high energy, high fat food is very useful. We can intellectually overcome our evolutionary drives when our environment changes.
The evolutionary pressures on the human species is rather different than those on other species. We have manipulated our environment to the point where normal pressures are different or absent. We have no major predators other than disease and old age; we on the whole are the predators. We live far longer than is evolutionarily useful — normally, an organism will live as long as it takes to breed and bring its young to a stage where they are secure and successful. We tend to live to about twice that age and we are working hard to extend that even further.
We don’t have to eat the foods our base desires tell us to, in fact it’s not even logical to do so
Our ability to survive as a species will be mainly down to our continued ability to change our environment, not so much on how we adapt to it. We don’t have to eat the foods our base desires tell us to, in fact it’s not even logical to do so. In the wealthier parts of the world we are not nutritionally short of anything.
So the next time you feel yourself reaching compulsively for things that your intellect tells you are of little nutritional benefit, you can blame the lesser evolved parts of your brain. They’re just doing their job.
The difficulty you experience comes from the fragility of our will-power. It’s so weak, that only the slightest distraction can break it. All it takes is a small “cognitive load” in our conscious mind and our brains’ capacity to resist is fundamentally undermined. But here we are again, we understand it. Our calorie-burning bonce has a wonderful logical, rationing side that lets us be aware of this weakness.
The trick with our weak will-power is to distract that too. Research shows that it’s not going to just go away and fighting it is not going to work either. No matter how many times you say “don’t picture a dancing elephant” — one will pop into your mind.
Understanding that the drive that pushes us toward that kind of diet is an ancient evolutionary one can be very useful. We can use the rational adaptive side to dull it down. In time we may develop a stronger intellectual reward system that gives us a boost in our pleasure centres when we do something logical. Perhaps, the master of the logical, Mr. Spock from Star Trek actually gets a great deal of pleasure from his behaviour, its just that he is able to outwardly be in control of that too.