Although this research has not studied the duration of friendships, it is possible that friendship length is a determining factor in the relation between mixed friendship quality and life satisfaction. (journals.plos.org)
Webster is now studying the duration of the hurricane season each year, from the first tropical cyclone to the last. (discovermagazine.com)
More controlled studies, with larger sample sizes and longer study durations are thus needed to bring clarification in this matter. (lift-heavy.com)