10) He laughs hysterically when watching swordfish (That movie was so stupid.)
9) He wears thick glasses even though his eyes are fine.
8) He consumes carbonated caffienated beverages at a rate that shames college kids.
7) When sleepwalking he talks in C. (Or other language that is computer oriented.)
6) He teaches a class at MIT.
5) He's Pizza Huts best customer.
4) He is at his computer at night frequently.
3) He's had only one sexual relationship in his life; it involved his hand
2) He frequently blows fuses from running three computers Simultaneously.
And finally the number one way to tell if your sons a programmer:
1) He makes twice as much as you and gets better benefits.