How do we make decisions?

http://www.youtube.com/watch?v=GGQLO_iXKlU

There have been many proposed theories on how we make decisions. But even the most supported theories cannot sometimes predict our behaviour, nor do they always lead to rational decisions. Prospect theory is widely supported by research, but it does not mean that it will lead to a rational decision. A good example of this is provided in the video by observing New York taxi drivers behaviour. The taxi drivers have a daily goal they would like to reach in business. On good days they reach their goal rather quickly and go home early, whereas on slow days they work very long hours trying to reach that goal. It would be more rational to work a bit more on good days and go home early in the slow days, but as prospect theory suggests they are not so motivated by their gains on good days to keep on working, as  they are by the losses on slow days. But it is interesting to know what happens in our brains when we make decisions.
Research has shown, that many of our decisions are based on emotion. Even in this video about prospect theory, the fMRI shows that the area activated in the brain during decision-making is indeed the amygdala- the centre of emotion. And as people can have various emotions on various times, it is not suprising then that people's decisions differ from person to person and from situation to situation.
Interestingly, the video also shows that small part of the frontal lobe is also activated during decision making and the extent of the activity differs from person to person. The area in the frontal lobe activated during decision making appears to be a controlling point for the amygdala, therefore controlling emotional responses. According to this some people are more in control of their emotions and are able to make more rational decisions than others.
This was to illustrate that most of our decisions are based on emotion and are not always rational.