Final answer:
Volunteering has been found to have positive effects on well-being and life satisfaction, especially in older adults.
Step-by-step explanation:
The research shows that compared to her peers who do not engage in any volunteer work, Mavis is more likely to be more satisfied with her life. Volunteer work has been found to have positive effects on well-being and life satisfaction, especially in older adults. The act of helping others and being engaged in community activities can provide a sense of purpose and fulfillment.