This book provides an approach to the research work done with people performing a stressful activity, capturing their biological data such as temperature, heart rate and blood pressure to verify the level of control they can have in simulated critical situations. A few decades ago, science and psychology knew very little about the mechanisms of emotion. But recently, and with the help of new technological means, the mysterious and obscure panorama of what happens in our organism while we think, feel, imagine or dream has been clarified for the first time. Thanks to the brain scanner it has been possible to unveil the function of our brains and in this way science has a powerful tool to talk about the enigmas of the heart and try to explain the most irrational aspects of the psyche. The concept of Emotional Intelligence has reached every corner of our planet. Daniel Goleman has tried to unravel the factors that determine the marked differences that exist.