This is one of those rare things in poker that I do very nearly 100% of the time, but JJ even UTG, I raise and usually I raise big, I want one or two callers.
Short of flopping a set, what does a good flop look like for JJ if no one raises for you? And if someone does raise, and you re-raise, the only hands that call you here have you beat or have a strong draw against you? If someone does raise, and you flat call, then you end up here...
As for the flop, to be honest I call here thinking he's open ended or has two pair. If he's got two pair I'm in a trouble but I've got outs, but I'm really expecting to see him turn over the straight draw.