With mirror neurons, we are able to observe, empathize, and learn from others. It is no wonder that we feel emotional pain and empathize with people who were struck by natural disasters and feel sexual excitement when watching sexual intimacy on screen or simply have social skills because we observe and learn from people around us.
This also leads me to think that do those with abnormal mirror neuron activities have psychological disorders? So I searched 'mirror neurons' some more on the net and found out that people with autism have mirror neuron deficiencies which causes them to lack social skills, learning skills, and imitation. However, I don't think mirror neuron deficiencies is the only effecting factor. Surely there are a number of reasons that can contribute to a person's lack of social or learning skills. People whose parents are abusive or persons with ADHD are general examples of this.