Kids learn the snub walk early on, not unlike the long stare the snub walk is designed to both intimidate and avoid contact.
Snub walks occure most commonly when you need your kid to do something.
Try asking them to clean up a mess and the snub gene will kick in, bam they’ll walk right by you, no eye contact or anything.
The long stare is similar in that they’ll appear to be focusing on something in the distance while you’re talking to them. Thus avoiding any interactions with you .