Psychology is growing and globalizing, as psychologist in about 70 countries around the world, and do research in many subfields. People who study psychology try to find out fundamental principles by which people can lead a happier and psychologically healthier life and to apply these principles to our daily life. As a science, psychology is rapidly evolving and provides the basis for study in various academic fields: liberal arts, social sciences, natural sciences, brain sciences, engineering, the performing arts, etc. With rapid advancements in technology and civilization, the issues concerning the quality of living are becoming more and more critical. These psychological issues cannot be considered without first considering the basic factors that constitute the science of psychology: sensation, perception, thought, personality, intelligence, and aptitude. Important as it is, psychology is also worth studying for its own sake, for human nature is a very interesting subject.