What would be a good introduction sentence to my "Nature V.S. Nurture" essay?

I have to write an essay for class discussing the controversial “Nature V.S. Nurture” argument, and I have to choose which one I think has a bigger effect on a person’s developing personality.
I have all the pieces of the essays put together, I have an outline even, but I simply, no matter how hard I try, I CANNOT think of a good sentence to start the introductory paragraph with. Any pointers/tips/ideas? Thank you!