the sample is randomly divided into 10 equal-sized subsets; 9 subsets are used to train the model (step 1), which is then applied to the remaining subset to predict the per- sonality score (step 2). This procedure is repeated 10 times to predict personality for the entire sample. The models are built on participants having at least 20 Likes. To estimate the accuracy achievable with less than 20 Likes, we applied the regression models to random subsets of 1–19 Likes for all participants.