Difference in rotation of ɡ2 stars relative to ɡ1 as a function of average pericentre distance over the past 500 Myr for a sample of clusters with multiple populations. The colour-coding shows the average eccentricities over the past 500 Myr. Positive values indicate that ɡ2 stars rotate faster than ɡ1 stars. The observational data on rotation are from Dalessandro et al. (2024), with orbital parameters from Baumgardt & Vasiliev (2021). The corresponding cluster names from the NGC catalogue are shown next to the data points.