Christian Bale GOOD GENES OR GOOD DOCS?

1/31/2016 12:00 AM PST

Christian Bale -- Good Genes Or Good Docs?

Holy smokes Robin ... Christian Bale has aged well!

Here’s a 25-year-old version of the "American Psycho" at a movie premiere back in 1999 (left) and 17 years later ... the iconic Batman -- who turned 42 this weekend -- on the red carpet earlier this month (right).

No Superman needed.

The question is...