I don't think anyone is born with it, but some of us are definitely better at being patient than others. Patience is a virtue that extends far beyond the publishing industry, and yet I feel writers are forced to practice patience far more than most.
I'd like to believe that practicing patience gets easier the further down the publishing path you travel, but I'm not sure that's true (I'll have to let you know).
Seeing patience is as integral to writing as editing is, how do you practice it?
Here's a couple tips I've adapted to help me:
1.Don't check your email after 7:30 p.m. You can let an agent, writer, editor, critique partner, ect. wait twelve hours to hear back from you. There's more to life than electronic correspondence. As much as I think living in the nineteenth century would annoy me, the thought of waiting weeks between correspondence excites me. Handwritten letters with wax seals, horse-drawn deliveries, and precious moments of solitude to respond sound perfectly wonderful.
2. Believe in yourself. So you haven't heard a peep from the last batch of query letters you sent out, that's okay. Go back to writing. That's the part you love anyway, right? Remember that you have awesome stories to tell--unique one-of-a-kind tales that have spun your imagination and heart more ways than you really know. While you wait, write. You never know what work of yours will sell.
3. Read. A good book always makes me want to write and reminds me that if this author could did it, so can I. You're anything but alone on your journey to publication. Draw your patience from others.
4. If all else fails, have a cocktail (or two). An inebriated mind doesn't mind waiting as long as the cocktails are cold and the company is good. Oh happy day!