Dateiii Student: Jennifer A. Mendiola I certify that this student has met the requirements for format contained in the University format manual, and that this thesis is suitable for shelving in the Library and credit is to be awarded for the thesis. Stress has negative consequences for well-being across the lifespan. Thus, social support, social strain, and control beliefs were examined in undergraduates and seniors (N = 364, ages 18 to 97, 72% women) for their relationships to multiple domains of stress.Hierarchical regression analyses controlling for demographics revealed that social strain was associated with partner (β = .26, p < .001), family (β = .29, p < .001), and friend (β = .27, p < .001) stress and perceived constraints were associated with financial (β = .26, p < .001), health (β = .33, p < .001), and work (β = .15, p = .017) stress, whereas social support (β = -.17, p = .006) was only associated with partner stress and mastery was associated with no domains of stress. Results suggest the importance of reducing social strain and minimizing constraints across the lifespan.