As your run() method does so little, one could not reasonably expect priority to have much effect. In fact, t1 may have started and finished, before the t2.start() statement even runs.
As previous poster has pointed out, Java makes few promises about exactly what thread priorities will do. This is to accommodate different platforms. In practice, however, JVMs on major OSs will respect priorities reasonably well. But, to see it, you'd need to give the threads worthwhile work to do: something that takes a few seconds (and don't use sleep(), wait() etc. because that's not work).
Betty Rubble? Well, I would go with Betty... but I'd be thinking of Wilma.