Sonja Lyubomirsky

Sonja Lyubomirsky, born December 14, 1966 in Moscow, is a Russian-born American social psychologist and Distinguished Professor of Psychology at the University of California, Riverside.

She earned her AB at Harvard and her PhD at Stanford under Lee Ross, and has spent her career running experimental studies on the determinants of human happiness, much of it supported by a multi-year grant from the National Institute of Mental Health.

Her popular book The How of Happiness (2007) translated this program for a general audience. Her best-known framework, developed with Kennon Sheldon and David Schkade, partitions chronic happiness into roughly three sources: about 50 percent attributable to a genetic set point, about 10 percent to life circumstances, and about 40 percent to intentional activity - the deliberate things people do and think.

The “40 percent” figure became her signature claim and the basis for an argument that sustainable well-being is largely buildable through practices such as gratitude, kindness, and savoring. It should be marked honestly: the specific percentages came from one model fitted to particular data, were always presented as approximate, and later researchers (including Lyubomirsky’s collaborators) have noted the partition oversimplifies how genes and environment interact.

Her interventions research has fared better than the headline number, though it too sits within positive psychology’s broader replication concerns.