This study aimed to reveal the association between spousal stress perception and marital instability across different stages of the family life cycle, focusing on the actor and partner effects and exploring the mediating role of daily communication in this relationship. With rising divorce rates, it's essential to examine factors affecting marital instability. Drawing from the stress-divorce model, spouses' stress perception likely permeates into marriage via daily communication. It is important to consider challenges unique to different marital stages to understand variations among couples through the family life cycle. The study used the Perceived Stress Scale, the Primary Communication Inventory, and the Marital Instability Scale to survey 654 couples in the newlywed, couples with pre-school children, couples with school-age children, and empty-nest stages. The study revealed that the actor-partner effects between stress perception and marital instability were initially present in the early stages of marriage. As the duration of the marriage progressed, during the stages of pre-school age and school-age children, only actor effects existed. In the empty nest stage, the actor-partner effects gradually diminish. Throughout the life cycle, daily communication served as a mediating factor in the relationship between stress and marital instability. This research uncovers a dynamic evolution in the association between couples' stress perception and marital instability across marital longevity: at the beginning of marriage, spouses have interactive effects
at the stage with child(ren), the interactive effect diminishes
at the empty-nest stage, the role is imposed only through the medium of daily communication. Our research reveals that maintaining communication during all stages of marriage is key to effectively managing stress and maintaining marital instability.