Emotions and Human Behaviour . Human behaviour depends on the interaction between the emotional and rational parts of the brain. The interactions of the lifes earliest years lay down a set of emotional lessons, based on the attunement and upsets in the contacts between infant and the caretakers. These emotional lessons are so potent and yet so difficult to understand from the vantage point of adult life. They are stored in the amygdala as rough wordless blue prints for emotional life. One reason why we can be so baffled by our emotional outburst is that these often date back to a time early in our lives when we did not have words for comprehending events. As we grow, we start harmonising emotion and thought we get a resultant behaviour. The connections between the amygdala and the neo-cortex are the hub of battles or cooperative treaties between head and heart or thought and feeling. The circuitry and the speed of response of the amygdala, explain why emotion is so crucial to effective thought; both in making wise decision and in simply allowing us to think clearly. The signalling of an emotion such as anxiety and anger can sabotage the ability of rational thinking. This is why, when we are emotionally upset; we say we just cant think straight. Continual emotional distress can create deficits in intellectual abilities. Nevertheless, emotions also have a powerful role in rational decision making. Dr Antonio Damasio, a neurologist at University of Iowa, has made careful studies of what is impaired in patients with damage to amygdala circuit. He found that their decision making was terribly flawed and yet they showed no deterioration at all in IQ or any cognitive ability. The problem therefore, is not with emotion as such; but with the appropriateness of emotion and its expression.