Final answer:
Research suggests that 50% of happiness comes from external circumstances, with social relationships playing a significant role in fostering happiness and good health.
Step-by-step explanation:
According to research, about 50% of our level of happiness comes from external circumstances, indicating that the other half of happiness is influenced by factors such as genetic predisposition and intentional activities. It's also noted that social relationships contribute significantly to happiness, as having close relationships with friends or family members provides not only happiness but can also foster good health and well-being. Factors such as a sense of control over one's life outcomes (internal locus of control) and being in a stable marriage can have positive effects on one's state of happiness.