Human behavioural patterns: A reality mining study

Mobile phone communication is a source of information for studying human behavioural patterns. A mobile phone can collect information of its usage, communication events and data captured by integrated sensors, and this information has been used for studying mobility, epidemics, health and depression, and information diffusion. Particularly, the call detail records have been used to study different social features, like the network structure, people's sleeping patterns, and response to natural disasters. They provides useful insights about the behaviour of the people involved in the calls. This dissertation is based on four research articles in which a huge data set containing call details records of around 3 million users over a 12-month period in 2007 is analysed, to study the dynamics of the human daily resting periods and human social focus over the life course. Each day, the calling activity of the mobile phone users follows two different circadian rhythms, each one synchronised to a different clock. On one hand there is the clock of social time, marked by social activities of the daily routine, in which the working and schooling times, opening times of offices, etc, set a specific social schedule to follow. On the other hand, some human physiological processes, like the human sleep-wake cycle, follow a natural 24h cycle, entrained to a biological clock. The calling pattern shows the struggle of living between these two clocks. It follows a specific schedule (it peaks and decreases twice each day, showing a strong dependence on social time). The location and size of the peaks of activity change over the year, by expanding during the summer and shrinking during the winter, thus indicating a seasonal dependence. Moreover, people living in the same time zone but at different locations, are found to start (or cease) their activity at different times, with a difference given by their local sun transit times, thus people living eastward in the time zone have earlier schedules than those living westward. The emotional closeness between users and their contacted alters can be determined based on their communication pattern. The level of interaction between a mobile phone user and the alters in his/her egocentric network is different, having a dominant interaction with the romantic partner. The features of the ego-centric network and the social focus invested on alters depends on the age and gender of the user, showing clear changes as the users go through different life course stages. Younger people contact more alters and more frequently but this changes noticeably as the egos cross the parenthood stage, in such a way that when egos reach old age, the size of the egocentric network has considerably decreased and it is mainly populated by alters younger then the ego. At the grand-parenting age, an important gender difference appears, when females (probably crossing menopause) show a strong change in social focus towards their daughters, who are in the reproductive stage, whereas males remain focused mainly on their romantic partners, providing supporting arguments for the grand-mothering hypothesis.