Even the chimps that were raised from infancy by humans, considered completely tamed, coddled and nurtured like human children, human rather than chimp identified, etc, etc have been known to maul humans for various reasons.
A caged zoo animal will have no compunction about stomping you flat, dismembering you and flinging your remains like monkeys throw poop if you come at it looking for a fight.
They are violent and moody like humans but many, many times stronger.