If Jasper is only a little over 1 year, now is the time to start working/training him to be a good housemate. Crate training, alone training, proper greeting training, etc etc. are all important items besides obedience training.
Is he put in the basement every time your son leaves but someone else is in the house?
If that's the case, then he just might develop SA associated with your son's absence. Does he have lots of toys and goodies while in the basement? Is he allowed to exit the doggie door when no one is home (very scarry thought)? How is he treated when your son returns - lots of hugs and attention (contributing to SA)?