Use the thumb or first finger on your right hand?

[jamint03]

Im teaching my five year old son! Should he start by using his right hand thumb to strike the string, or use his first finger?
Does either way depend on what style of bass he is eventually going to play? If so, he seems to like the slap/funk bass style as of now. Any other tips for a 5 year old and a teacher (myself-dad) that is a very average player at would be appreciated. Thank you

[Dazzare]

Anthony Wellington "Four Levels of Awareness" for a musician. From Victor Wooten:Groove Workshop - YouTube
Watch the Video and Just let the kid have fun!

[DeadHeadSF]

I sometimes use a thumb + finger playing style carried over from guitar. Nothing wrong with learning both ways. The earlier they learn, the better they'll be.

[mambo4]

If teaching him the most useful habit is desired, I'd say tech him to pluck with his first finger -going on to the first 2 fingers. Thumb is most often for slap, which is a small fraction of what a bass guitarist typically does.

[ksandvik]

Thumb playing has its uses outside slapping but yes it's better to start with the first two fingers first to get the left hand/right hand coordination in place.