What do you think of Genetically modified wheat? It is a complex issue. You don't want to answer to hastily. Rational approach would be to consider the controversial technologies pros and cons separately. write down the possible benefits weigh them in terms of importance, and then multiply them by the probability that they will occur. Doing so you get a list of expected values. Next, with the cons. List all the disadvantages, estimate their potential damage and multiply them by the likelihood of them happening. the positive sum minus the negative sum equals the nett expected value. If it is above zero you are in favour of Genetically modified wheat. If the sum is below zero, you are against it. More than likely you have already heard of this approach. It is called 'expected value', and it features in most literature on decision theory. But just as probable is that you have never bothered to carry out such an evaluation. And without a doubt, none of the Professors who wrote the text books turned to this method to select their spouses.
Truth be told no one uses this method to make decisions. First of all, we lack imagination to list all the possible pros and cons. We are limited by what springs to mind; we can only conjure up what we have seen in our modest experience. It is hard to imagine a storm of the century if you are only thirty years old. Second, calculating small probabilities is impossible because we do not have enough data on rare events. the smaller the probability the fewer data points we have and the higher the error rate on the exact probability; a vivacious effect. Third, our brain is not built for such calculations. they require time and effort - not our preferred state. In our evolutionary past, who ever thought too long and hard vanished inside a predators jaws. We are the dissidents of quick decision makers, and we rely on mental short cuts called heuristics.
One of the most popular is the affect heuristic. An affect is a momentary judgement; something you like or dislike. the word gunfire triggers a negative effect. The word luxury produces a positive one. This automatic, one dimensional impulse prevents you from considering risks and benefit to be independently variables which indeed they are. Instead, the affect heuristics puts risk and benefits on the same sensory thread.
You emotional reactions to issues such as neuclear power, organic vegetables, priviate schools or motorbikes determine how you assess their risk and benefits. If you like something you believe that the risks are smaller and the benefits greater than they actually are. If you dont like something, the opposite is true. risks and benefits appear to dependent. Ofcourse, in reality, they are not.
