Serious question actually. When would you expect children to have some empathy with other people?
Last night dh learnt that his dad has had a serious stroke and we spent the night urgently finding him a flight to travel to see his father very possibly for the last time (lives in another country.) 
Dh is not surprisingly emotionally wrecked and weepy. Ds 1 and 2 (7 and 9) have reacted with total lack of concern for dh. They don't know their grandfather very well so their lack of concern for him is not surprising BUT in spite of me explaining very clearly that their dad is very sad and very worried because his father might be dying they have behaved as if nothing at all has happened e.g. pestering dh to give them piggy backs, the usual silly boys jokes about bottoms and ds1 even said to dh 'I hope you don't come back' when dh left this morning for the airport because he (ds) thought it was funny. This behaviour was in spite of me taking them to one side several times and saying that dh and I were feeling very sad so now is not the right time for jokes - it's time to be kind by helping with best behaviour etc etc.
TBH I'm shocked and upset by their callousness. I really didn't expect them to 'understand' grief and adult emotions but at 9 I expected at least ds1 to make an effort when it was pointed out to him.
Am I expecting too much from them or am I rearing a pair of sociopaths???