My favorite animal is the monkey.  Do you like monkeys? 
I love monkeys! and they are generally considered very intelligent, specially Old World monkeys.
What distinguishes Old World monkeys from New World ones? 
Old World monkeys are from Africa and Asia and New World monkeys are from South and Central America.
Why are old world monkeys more intelligent than new world? 
I don't know that or even if that is true is what is believed. Of course there are also the Hominoid apes (e.g gorillas and chimpanzees) that lack a tal.
Ah yes the apes though are not as fun as monkeys in my opinion.
Ape
Apes (Hominoidea) are a branch of Old World tailless simians native to Africa and Southeast Asia. They are the sister group of the Old World monkeys, together forming the catarrhine clade. They are distinguished from other primates by a wider degree of freedom of motion at the shoulder joint as evolved by the influence of brachiation. In traditional and non-scientific use, the term "ape" excludes humans, and is thus not equivalent to the scientific taxon Hominoidea. There are two extant branches of the superfamily Hominoidea
A group of monkeys may be commonly referred to as a tribe or a troop.
Two separate groups of primates are referred to as "monkeys": New World monkeys (platyrrhines) from South and Central America and Old World monkeys (catarrhines in the superfamily Cercopithecoidea) from Africa and Asia. Apes (hominoids)—consisting of gibbons, orangutans, gorillas, chimpanzees, and humans—are also catarrhines but were classically distinguished from monkeys. (Tailless monkeys may be called "apes", incorrectly according to modern usage; thus