> Dont over estimate how dumb they are.
Somehow, I can't parse this.
Somehow, I can't parse this.
Now on this scale estimate how dumb someone is. If you say 2 (a little dumb) but in actuality they’re a 7 (very dumb) you underestimated how dumb they are.
See? He overestimated how dumb crooks are, and was robbed.
Totally changes the meaning of the comment if one assumes that it was a typo and OP intended to use "underestimate".
"Don't overestimate how dumb they are" is logical and correct. However, because "how dumb they are" is in the sentence, it emphasizes, well, that they are dumb, which is not what the OP intended to say.
Writing it as "don't underestimate how smart they are" is more readable, although logically, it's stating the same thing.
Even better, I would have written it as "don't underestimate how smart they can be."