Our brains are much more complex and developed than animals. The fact that our heads have evolved to become so big, to accommodate our large brain, is one of the key reasons that child birth in humans is so difficult and painful. However, even in reptiles that have very small brains, there are commonalities in brain structure, that control the most basic decision making, that drives a fight or flight response to danger. Analysis of our brains, indicates that the signals that arrive in our limbic centre, the source of our emotions, arrive much faster than the slower but more accurate prefrontal cortex part of our brain that is responsible for thinking and analysis. When faced with a decision we have the instant, albeit fuzzy knowledge that this decision will be rewarding or threatening to us. After that, our thinking brain is usually just trying to justify the decision that we have already made in our gut.
This was beautifully illustrated recently as I watched with amusement as a friend of mine, who has just turned 40, was trying to justify why buying a Porsche is a really sensible idea. He argued that his current car is costing money on maintenance and how a second hand Porsche is actually cheaper than many family sized 4x4's. Being a family man he wants to be convinced that this is a really logical and sensible decision and any good sales person would jump on that and close the deal. The emotional battle was won at the start, now he needs some logical "sensible" arguments needed to put his cognitive dissonance to rest, and actually buy the car.
In the workplace, it is helpful to recognise that decisions are indeed emotionally driven and take that into account for your own decision making, as well as using it to your advantage when trying to get other people to make decisions.