He 's shy , polite , thoughtful , sensitive , soft - spoken , artistic , and intelligent .
Whereas Mark acted like a rebellious delinquent at first , David is friendlier to the Conners .
Mark 's shy , polite , thoughtful , sensitive , soft - spoken , artistic , and intelligent .
Whereas Mark acted like a rebellious delinquent at first , David is friendlier to the Conners .