The Usual Mistakes Are Opposites
Young characters get written as loud, impulsive and stupid. Old characters get written as slow, wise and tired. Both are the same error — treating age as a personality type rather than a position in a life.
The differences that read as true are structural, not tonal.
Age Changes the Time Horizon
A nineteen-year-old thinks in weeks and believes situations are permanent. A sixty-year-old has watched enough situations end to know this one will too, which reads as calm and is actually pattern recognition.
Write the horizon, not the mood. A character who assumes this will pass behaves differently from one who assumes this is forever, in every scene, without ever mentioning their age.
Older Characters Have More Ruled-Out Options
Youth is defined by openness — anything could still happen. Age is defined by closure: some things are now decided. Not always sadly. A character who knows they will never leave this town can be at peace with it, and that peace is far more interesting than weariness.
Younger Characters Are Not Less Competent
They are less experienced, which is different. A young character can be extremely good at something and still misjudge people, because skill accumulates faster than judgement. Writing youth as general incompetence is both inaccurate and boring.
Watch the Reference Points
What a character finds normal dates them more than anything they say. What technology they had to learn versus grew up with. Whether they treat a phone call as intimate or intrusive. These are quiet and they do enormous work.
Children Should Be Certain
The most common failure with child characters is making them wise. Real children are confident about things they have no basis for, deeply serious about their own logic, and often unnervingly direct. Certainty is the note, not innocence.
Ask What They Have Already Survived
The single most useful question for any age. A twenty-year-old who has already lost a parent is not writing from a twenty-year-old's position. Age gives you a default; history overrides it, and history is what makes a character specific rather than a demographic.
