. . .

I am a neuroscientist and like, for example, Antonio Damasio's work on the function of emotions in decision making - there is a lot of info online and he wrote a few books as well. . . I personally like to approach it in this more organic way, looking at how the brain works and regulates behaviors, rather than the (for me) more esoteric, older theories in classical psychology that do not go very far in terms of causality. Emotional regulation and dysfunctions are not so much different from the regulation of other physiological processes, like reactions to physical pain, it's all biochemistry.

As for the function of emotions (both positive and negative), I think it's more complex than just protective. They play integral part in every decision making process, including unconscious ones (which are the majority anyway). . .They are the inner responses to perceptions - accurate ones and imagined. If they are out of balance, it can lead to distortions in our image of reality (okay, not getting into what "reality" is...) and in our responses, both in feeling and actions.

Early life experiences are especially important in setting up the mechanics of individual emotional regulation because the brain and our whole system is developing until our ~mid-20s, thus more vulnerable. Adverse life experiences in childhood and adolescence can interfere with the balance and functioning of this developing system, and often the effects become very persistent and life-long. . .

. . .

All this reminds me of what many therapists claim because it's their work, about the "transforming" effect of increased awareness. . . But my biggest criticism about the power of psychotherapy goes back to what I said above. It can affect some of those old, ingrained neurobiological processes that cause problems in functioning, but in most cases nearly not enough, in order to make serious changes. . .