I would not consider David Hawkins to be a credible source. His PhD was from a degree mill that was shut down by court order. He has been flagged by the Cult Education Institute and Quackwatch.
Emotional energy is not quantifiable in a physical sense. Most studies on the subject use a proxy for physical well-being such as vagal tone (Kok et al., 2013) or corrugator EMG/galvanic skin response/etc. (Witvliet et al., 2001). The general consensus of these studies are that forgiveness and pro-social behavior do lower both perceived (patient-described) and physiological markers of stress. That is, that being a pro-social person seems to be actually healthy.
In terms of emotional neglect leading to poor health, the most infamous experiments were performed by psychologist Harry Harlow, which he reported in "The Nature of Love" in 1958. His experiments focused primarily on maternal bonding, demonstrating that infant monkeys will most often choose the comfort of a mother-monkey effigy over food. These studies do seem to indicate that there is something crucial about positive socio-emotional contact that promotes well-being in primates.
Many psychologists and social neuroscientists are researching the effects of pro-social behavior, neglect, and stress. There are scientific journals dedicated to the subject (viz. Child Abuse & Neglect).
If you are interested in the question of why everyone doesn't stop behaving in a cooperative manner, there are many papers on the subject. Researchers are indeed looking into the matter:
Behavioral economists want to understand how collaboration builds economic societies. That is, the balance between pro-social behavior and selfishness that drives economics. (Bowles & Gintis, 1998)
Sociologists and social policy researchers want to understand the societal effects of neglect, abuse, and cooperation in order to understand the dynamics of large groups of people and to design better policies to improve the well-being of those societies (and the people in them). (Frey & Meier, 2005)
Evolutionary biologists, psychologists, and social neuroscientists want to understand the biological mechanisms that underlie pro-social behavior and its effects on reproduction and survival. (Lukas et al., 2011) (Frey & Meier, 2004)
Synthetic biologists and microbiologists are attempting to understand how colonies of bacteria solve these problems in the microbiome, in order to survive and propagate.
Bowles, S., & Gintis, H. (1998). The moral economy of communities: Structured populations and the evolution of pro-social norms. Evolution and Human Behavior, 19(1), 3-25.
Frey, B. S., & Meier, S. (2004). Pro-social behavior in a natural setting. Journal of Economic Behavior & Organization, 54(1), 65-88.
Frey, B. S., & Meier, S. (2005). Social Comparisons and Pro-Social Behavior. American Economic Review,(forthcoming).
Harlow, H. F. (1958). The nature of love. American psychologist, 13(12), 673.
Kok, B. E., Coffey, K. A., Cohn, M. A., Catalino, L. I., Vacharkulksemsuk, T., Algoe, S. B., ... & Fredrickson, B. L. (2013). How positive emotions build physical health: Perceived positive social connections account for the upward spiral between positive emotions and vagal tone. Psychological science, 24(7), 1123-1132.
Lukas, M., Toth, I., Reber, S. O., Slattery, D. A., Veenema, A. H., & Neumann, I. D. (2011). The neuropeptide oxytocin facilitates pro-social behavior and prevents social avoidance in rats and mice. Neuropsychopharmacology, 36(11), 2159-2168.
Witvliet, C. V. O., Ludwig, T. E., & Laan, K. L. V. (2001). Granting forgiveness or harboring grudges: Implications for emotion, physiology, and health. Psychological science, 12(2), 117-123.