Behavioral consistency in the digital age

https://journals.sagepub.com/doi/10.1177/09567976211040491

Efforts to infer personality from digital footprints have focused on behavioral stability at the trait level without considering situational dependency.

We repeated a classic study of intraindividual consistency with secondary data (five data sets) containing 28,692 days of smartphone usage from 780 people.

Using per-app measures of pickup frequency and usage duration, we found that profiles of daily smartphone usage were significantly more consistent when taken from the same user than from different users (d > 1.46).

Random-forest models trained on 6 days of behavior identified each of the 780 users in test data with 35.8% accuracy for pickup frequency and 38.5% accuracy for duration frequency. This increased to 73.5% and 75.3%, respectively, when success was taken as the user appearing in the top 10 predictions (i.e., top 1%).

Thus, situation-dependent stability in behavior is present in our digital lives, and its uniqueness provides both opportunities and risks to privacy.

Here, we considered consistency in digital behaviors, through studying the variation of engagement (a behavior) across several nominal situations (apps), collected unobtrusively every second across several days. We found that smartphone users have unique patterns of behaviors for 21 different apps and the cues they present to the user. These usage profiles showed a degree of intraindividual consistency over repeated daily observations that was far greater than equivalent interindividual comparisons (e.g., a person consistently uses Facebook the most and Calculator the least every day). This was true for the daily duration of app use but also the simpler measure of daily app pickups—how many times you open each app per day. It was also true for profiles derived from individual days and profiles aggregated across multiple days. Therefore, by adopting an interactionist approach in personality research, we can predict a person’s future behavior from digital traces while mapping the unique characteristics of a particular individual. Research indicates that people spend on average 4 hr per day on their smartphone and pick up their smartphone on average 85 times per day (Ellis et al., 2019). It is important that theories can adapt to the way people behave presently in digital environments.