A multilevel mixed-effects linear regression.

Regression performed with the number of points that individuals collected during each day. We distinguish five models as discussed in the main text. The independent variables are the Points participants collected the previous day, group level information of the previous day (the number of Points per person, the number of chat messages, number of Likes), and dummies for the treatment participants were in. We controlled for group effects for performing a multi-level analysis where we indicated the groups participants in. The χ2 was not significant which means that there was no significant group effect on the error terms. For each variable of the regression we provide the estimated value, the standard deviation (between brackets), and the 95% confidence interval.