I think I understand most of the emotions and what they are good for. I am in favor of them all. Fear, anger, and anxiety activate in order to keep you from being eaten and they get you out of bed in the morning. Lust, love, hunger, and greed provide direction and lay the foundation for satisfaction. Jealousy, guilt and shame reinforce love in cementing loyalty to the family, the pod, and other institutions. The list of useful emotions goes on and on.
All emotions have both physiological and cognitive elements. You literally feel a certain way in your body, but you also think something about it. Because of this interpretative element, most emotions can be experienced as some form of exhilaration, the realization of which is exhilarating in its own right!
And then there is depression, which really sucks. Depression replaces motivation and activity with pain and paralysis. Depression reduces communication to the expression of suffering. Depression is simply debilitating. In evolutionary terms, emotions are enormously complicated and expensive so each of them must be very important. Or must have been important at one time. I cannot understand the utility of depression in our modern context so I must defer to the best historical theory I know about it, which is that it takes us down so that the alpha male in our group doesn't have to beat us to death. Specifically, when we come to the conclusion that we are inadequate to our aspirations, depression encourages us to abandon the struggle that might get us killed. Depression convinces us to lie down. We may be miserable but we can still propagate. This makes perfect sense in the brutally competitive primate environment of our forbears, but it is not desirable in the this day and age.
Depression can affect the psychological and social aspects of life that influence a person's ability to manage his/her daily functions. It is one of the most serious obstacles to progress in counseling and psychotherapy and must be gotten out of the way. Fortunately, we actually do live in civilized times rather than in a primate jungle and cognitive therapy works for depression in this society, sometimes in combination with a course of medication. There are too many exhilarating possibilities in life now, to spend much time in depression.
Reference: Joe Ferguson, PhD
Dr. Ferguson is a PhD in Clinical Psychology, Fielding University. He obtained a MBA, from Wharton School of Business. He can be reached at 332 Forest Ave., Suite #17, Laguna Beach, CA 92651