Why is the Vervet monkey study "really dumb?"

I understand that, Marlow, but the reason why she's using monkeys is at all is because any time humans are used, regardless of age, we can't rule out the possibility that, even at such a young age, there could be a preconceived bias from observations in society. The real problem with this kind of study at all is that it's impossible to do any kind of double-blind study involving humans. Primates are all we have.

1, Why use vervets rather than chimps or bonobos which are phylogenetically closer to us? 2, It's still meaningless. Vervets have no concept of cooking or fire trucks.