Creating a compelling character is more than picking a name, race, and gender. Readers need to invest in your characters. For that to happen, a writer must give their characters back-stories, families, flaws, motives, well-rounded personalities, etc. Given this, some may consider basing their characters on family, friends, foes, teachers, movies stars, or that creepy guy they saw at the gas station last week. So the question remains, should writers base their characters on real people?
The truth is, there is no right or wrong answer here. I personally shy away from incorporating people I know into my stories. When I write a character, I need the freedom to develop and grow their personalities. If I based a character on a person I knew, it would be more difficult to allow the character to flourish and fulfill their purpose in the story. I would always see the character as my friend or my classmate. If I needed the character to do something atrocious or pick a fight with the underdog, I would have a hard time separating the action of my character with the action of my real-life friend or classmate.
Instead, I like to base my characters off of a group of people--it seems less personal that way. During my middle and high school years, I could not stand math classes. They seemed like pure torture. As a result, I seldom met a math teacher I admired. In my recently completed manuscript, the main character is a high school student. When I had to write her math teacher, I did not base him off of any one of my middle or high school teachers. I compiled a mental list of the traits my math teachers had in common, the mannerisms they shared, and the type of clothes they wore. When I think of the math teacher in my manuscript, my mind does not picture one specific man or woman. An image of a typical and realistic math teacher is formed. From there, I was able to build my main character's math teacher. I assembled a unique back-story that would explain his abrasive personality, but more importantly, I created a flexible character. By basing the foundation of my character on an, albeit stereotypical, image of a math teacher, I armed myself with autonomy. In other words, I cut the strings that would otherwise hold my character to the limitations and the motivations of a person I actually knew.
Are you ready for the contradiction? Though I avoid basing characters on real people, I have made one small exception. One character, that plays a minor role in my manuscript, was originally based on a real person. My main character's English teacher, Mrs. Walden, who only appears a few times, was modeled after one of my real-life high school English teachers. Mrs. Walden's (the character and the real person do not share the same last name) physical and personality traits closely resemble that of my high school teacher. However, I have not seen or heard from my real-life English teacher since I graduated (not telling how many) years ago. That being said, my real-life teacher is now somewhat of an abstract figure. Also, as the story has progressed, Mrs. Walden's character has evolved into her own person. So again, should you base your characters on people you know? If you can create enough separation between the real person and your character, than I say, go for it! Just be careful. Do not limit the potential of your characters simply because their real-life counterpart would never do, say, or think like that.