Introduction: The spillover effect is the psychological overflow due to daily stress in one context and the transfer of its consequences to another close environment. The aim is to explore the spillover effect in conflicts within the family, on the one hand, and school with peers on the other hand, as an inferred measure of daily stress according to the literature. Method: The study consisted of a sample of 208 6-year-old students and their families. A methodology based on daily report records was used, by means of two ad hoc checklists with simultaneous measurements, for 2 consecutive weeks and 3 academic years, for both family and school contexts. A repeated measures design, together with a nonparametric statistical data analysis with Friedman’s test and contrast measures, was used. Results: Daily stress shows significant differences in the family setting throughout the week (χ2 = 32.44; p = 0.000) and at different times of the day (χ2 = 29.65; p = 0.000). In the school setting, differences were found across the different days of the week (χ2 = 36.96; p = 0.000). Spillover effect has been discovered between conflicts at home in the evening and conflicts at school. At the same time, conflicts at school are related to conflicts at home from Wednesday onward.
Discussion: The results suggest further research on daily stress through the interrelation of the different contexts, as well as the impact that moments of conflict may have on the psychological and emotional development of the child.