Feelings of well-being and happiness are important to overall physical and mental health. People with higher well-being are found to live longer, healthier and more successful lives. In most research, well-being is assessed at a single time point. However, like many complex human traits, feelings of well-being fluctuate over the day or week and across contexts. Furthermore, some people show relatively stable levels of well-being over time and across contexts, while others fluctuate a lot. In a genetically informed study, we investigate the individual differences in daily, weekly and seasonal patterns of well-being and the interaction with the social environment in a large sample of twins of the Netherlands Twin Register.

The approach includes multiple assessments of well-being, whereabouts, and social interactions per day, and continuously passive sensing of the (social) environment, phone use and physical activity for 28 days throughout the year (a week each season). A subset of participants receives Bluetooth beacons to supply to individuals in their social network (e.g., friends, co-twin) to objectively assess proximity of these individuals on a daily basis.

This genetically informed design and combination of active and passive data collection results in a large data set that can lead to new insights about the fluctuations of well-being and more knowledge about what makes people happy.