A theoretical model in social psychology and family relationships that describes changes in marital satisfaction (see MARITAL SATISFACTION) in a relatively linear and stable manner over time. This model was designed to offer an alternative perspective to curvilinear models of marital satisfaction, assuming that the factors influencing marital satisfaction act cumulatively or gradually, rather than subject to significant fluctuations at different stages of life. This analytic model demonstrates that marital satisfaction changes gradually and continuously throughout a marriage, reflecting the combined influence of personal, interpersonal, and social factors, with satisfaction increasing or decreasing depending on marital experience, without the sharp fluctuations assumed in curvilinear models.