Even though the idea of compassion lies at the heart of virtually each and every religious and spiritual movement (with Buddhism and the Dalai Lama problably being the frontrunner), psychological science has ignored this important feature of our human nature for quite a long time, describing it as a subtype of other, more primary emotions. Starting with research on meditation, such as carried out by pioneers such as Jon Kabat-Zinn, the topic has slowly but surely entered the “regular” academic discourse. Nowadays, the science of compassion is a full-blown discipline, being researched, e.g., at Stanford´s Center for Compassion and Altruism Research and Education (CCARE) or Berkeley´s Greater Good Science Center (GGSC).
In 2010, researchers Jennifer L. Goetz, Dacher Keltner, and Emiliana Simon-Thomas authored a review article that sought to make a case for the idea that compassion is a truly distinctive feature on the continuum of human behavior and emotion. Here´s what they have to say in their conclusion:
Our review reveals compassion to arise out of distinct appraisal processes, to have distinct display behaviors, distinct experiences, and an approach-related physiological response. The state like experience of compassion, and the trait like tendency to feel compassion, fall under the purview of three evolutionary arguments: that compassion evolved as part of a caregiving response to vulnerable offspring, that compassionate individuals were preferred in mate selection processes, and that compassion emerged as a desirable trait in cooperative relations between non-kin.
If you want to hear the full story, please read the aforementioned article. You may also want to watch this TEDx talk by Dacher Keltner (who´s the director of the aforementioned GGSC). Enjoy!