Opposites: black/white (The Defiant Ones), neat/sloppy (The Odd Couple), East/West (Shanghai Noon). The list is never ending. Why? Because in screenwriting when you force opposite characters to interact with each other, sparks fly. Conflict! Tension! Obstacles! This is writing gold and the stuff screenwriting is made of.
Yet understanding the polarity of each character's position is crucial, and for the most part, it comes down to research and objective listening with understanding. However, one of the most difficult character oppositions to tackle is also one of the most common and certainly one in which most of us live every day: Man vs. Woman.
She likes to talk. He likes action. She shares her problems. He wants to fix them. She wants eye contact, but he's watching the game. She expects listener noise: "Really? You don't say. What a jerk!" but when he listens, he really listens – silently. Conflict! Conflict! Conflict! And great, great stuff for the screenwriter.
Men are from Mars, Women Are from Venus. You've heard the phrase, maybe even read the book – and as the title suggests, men and women are as different as being from other planets. And ain't that the truth! I'm married with children (two girls and a boy), and at least in my world, I see the conflict of alien planets every day.
But you don't have to have a PhD, be in a relationship, or have children to understand the gender dynamic; however, it is helpful to become a bit of a popcorn psychologist – because you must create plausible and believable situations where your characters (men and women) interact.
Books such as Dr. John Gray's Mars/Venus series can be a useful resource, helping you understand the communication breakdowns, style, and emotional needs of the sexes. And if you can grasp it, your script will show it. And then if you're lucky, you'll even learn a thing or two and apply it to your own interpersonal relationships. Think about it, becoming a better writer can absolutely make you a better person.