Ron Artest III -- I Don't Call My Dad 'Metta' ... His Name's Ron

There's one place Metta World Peace isn't Metta World Peace ... his own home.

We spoke with Ron Artest III -- who tells us behind closed doors, the Lakers star is simply Ron, just like his mother named him.

By the way, RA3 is a prep basketball superstar who's being recruited by colleges all over the country ... and oh yeah, THE KID CAN DUNK!!!

He also gave us some insight into Christmas at the Artest home ... and let's just say they ain't the Kardashians.