Men and women may be equal, but they are different — and for a writer trying to create characters of the opposite sex, getting a handle on those differences is both important and difficult. We tend to create characters who think and talk like us. That’s how female writers end up creating men who come across as highly emotional, and that’s how male writers end up creating women who come across as tough, gruff, and abrasive.
First, a disclaimer: Gender differences are tendencies, not hard rules. Every human being falls along a spectrum between what society perceives as “masculine” and what society perceives as “feminine.” Where each person falls on the spectrum often reflects things like family of origin, ethnicity, age, education, and profession.
The challenge is in learning to step back from what WE would do to consider what THIS CHARACTER would do, to step back from what WE would say to consider what THIS CHARACTER would say.
Still, there are key differences between men and women. Being aware of those general differences will help you create believable (but not stereotypical) characters who think, talk, and act in gender-appropriate ways.