  We study correlations in temporal networks and introduce the notion of
betweenness preference. It allows to quantify to what extent paths, existing in
time-aggregated representations of temporal networks, are actually realizable
based on the sequence of interactions. We show that betweenness preference is
present in empirical temporal network data and that it influences the length of
shortest time-respecting paths. Using four different data sets, we further
argue that neglecting betweenness preference leads to wrong conclusions about
dynamical processes on temporal networks.
