Empathy is important for our growth, development, and survival. The ability to empathize is directly wired into the neural circuits of the brain, and in particular into two distinct but interconnected areas of the brain - the amygdala and the neocortex. The amygdala is part of the primitive brain or limbic system. The amygdala is the emotional brain, the part of the brain that rapidly generates desire, rage, madness, extreme joy, and the place where tears are generated and our most meaningful personal memories are stored.

The most powerful question the amygdala asks about every person we face and every situation we find ourselves in is: am I in danger of being hurt? If the answer is yes, the amygdala immediately sounds the alarm, stimulating the production of hormones, mobilizing the muscles to get to work, getting the blood flowing to the heart, and entering into a state of “fight or flight” readiness. This automatic response to danger, whether real or pre-determined, is called the “fight or flight” response, and anyone who has experienced an anxiety or panic attack can attest to the amygdala's ability to generate strong emotional responses. In the distant past, the amygdala ruled all the neural circuits in the brain, acting as a master console, producing automatic responses to different physical threats. Then, about 100 million years ago, mammals began to evolve a new layer of brain cells for accomplishing goals that required more reason. The neocortex, or thinking brain, wrapped like a thin blanket around the outside of the primitive limbic system, allowed mammalian ancestors to reflect on their feelings and regulate their behavior based on this considered feedback. For example, amygdala-dominated snakes and frogs would eat their newborn babies when they were hungry (and what's more, they wouldn't feel guilty or sad about it at all), while neocortex-dominated mammals would sacrifice their own lives rather than protect their offspring.
Over millions more years of evolution, an interplay between the thinking brain and the emotional brain developed that allowed for dispensing calm reasoning to fiery emotions, allowing time for thought before giving feedback, slowing down the process of automatic emotional responses. The basic emotions of fear, anger, sadness and joy gradually expand into more subtle and complex experiences. Anger, for example, differentiated into such complex emotions as annoyance, resentment, and indignation; contentment evolved into feelings of delight, pleasure, intoxication, and extreme happiness;
Devotion evolves into caring. Emotions like self-pity, despair, embarrassment, and humiliation also become part of the full reservoir of human emotions. Altruism and self-sacrifice appear in our vocabulary as we develop the ability to prioritize the needs of others over our own. The most recognizable expression for small children is happy, followed by sad, angry and fearful. By the age of four or five, children are able to accurately name these basic emotions, although there are many researchers who believe that children understand these emotions long before they develop language skills sufficient to describe them. Some of the more complex emotions, such as shame, contempt, and disgust, are much more difficult to understand, and as researchers say, these require a few more years of brain development and experience with relationships. By the age of 6, children can understand that there can be a difference between people's real emotions and the ones they show, and around age 7, they can understand situations that involve the emotions of jealousy, worry, pride, humility, and guilt. As children are able to consider not only nonverbal cues like facial expressions and body movements, but also verbal cues like tone of voice, they become increasingly able to discern motives and intentions for behavior. By the age of 9-11, children are able to recognize from nonverbal communication that
Whether others are trying to deceive and manipulate them.
No matter how old a child is, if they are soothed when they cry and hear the laughter of others when they laugh, they will believe that the outside world will respond to their emotions in a soothing way. But if their tears are always uncared for and their fears are always ignored, then they assume that the world is unresponsive and doesn't care about them. If they are always ignored in this way, their emotional response narrows and fear becomes the dominant of all emotions. In other words, early experiences of interaction with loving and focused people gently nurture and strengthen the neural circuits that produce empathy, and this prevents dramatic swings in our emotions. In contrast, repetitive interactions with an angry, violent, or neglectful nurturer can short-circuit the neural pathways through which one sends or receives empathy. If we find out over and over again through a particular emotional pathway that the world can't always get it right or doesn't care how we feel, then we eventually realize that there's no point in continuing to try and start shutting down our emotions.