Study of emotions has gone through investigations in various different prespectives: psychological, philosophical, computational, neuro-biological, evolutional and so on. Reseachers from different areas have defined various models for studying emotions and other related stuffs. But till now there is no universally accepted model. Partially this is due to the lack of proper definition for emotions itself. According to this article published in 1981 there are 91 definitions for emotion defined by various people from different areas.
First we have to agree on the following hypothesis in order to understand the evolutionary traits of emotions:
“Every human/animal or (may be?) any biological system tries to survive, by some means, any kind of internal or external attacks”
What would have been the main objective when human/animal started to live in this world? Obvious. Yes, it is Survival! First, the body has to take care of its equilibrium. Then he (see the note1 given in the bottom!) has to defend himself and survive any internal or external attacks; find something to eat or drink to energize his body. Once this two things are more or less guaranteed then he can think about pleasure, happiness, joy, fun, passion, setting/achieving his goals and so on. This is the philosophy of any human-being. Now we try to relate this philosophy to the following:
Homeostasis takes care of the internal imbalances in our body and keeps our body in an equilibrium. Hence it takes care of the physiological part and makes him survive the internal issues in his body. Once this is taken care he thinks about the survival from the other external things/forces. For this the evolutionary extension called as emotion helps. If he is faced with many issues emotions tell him which one to take first. It also helps him to interrupt what he is doing and makes him to be ready for the situation. Emotion also helps him to communicate instantly and to apply it as a problem solving tool (that is to take action to survive the dangerous internal and external events). Once these two levels are taken care the next stage of evolution is cognition where he is able to use the information, gain knowledge, analyze, infer, apply logic, compute and build new things from whatever he knows. So the emotion can be called as a “evolved supervisor” for homeostasis while being at the service of homeostasis and likewise cognition can be called a “evolved supervisor” for emotion while being at the service of both the homeostasis and emotion. This evolution does not mean that its one way, i.e., homeostasis -> emotion -> cognition. The evolution has come to a stage where all three are interdependent. This shows that the evolutionary perspective of emotions but there are other models too in the literature that are different from the above. For example, of the many, three of them are
- James-Lang Theory
- Cannon-Band Theory
- Two factor theory
We will discuss about these three in the next post.
Note1: Those who feel that I am a male chauvinist please replace he with she and him with her wherever appropriate!
Note2: This is with respect to the second post on emotion vs thinking, Marvin Minsky, in his book The Emotion Machine, feels that the emotion is not especially different from the processes that we call ‘thinking’ (see this).