Howler monkeys have smaller brains than equally sized spider monkeys.This is thought to stem from the fact that:
A) howler monkeys eat more fruit than spider monkeys.
B) howler monkeys eat less fruit than spider monkeys.
C) howler monkeys eat less meat than spider monkeys.
D) howler monkeys live in larger social groups than spider monkeys.

Question

Quizplus · Accepted Answer

Studies have shown that spider monkeys have a diet that is higher in protein and fat from insects and small animals, which may contribute to their larger brain size compared to howler monkeys, who have a primarily fruit-based diet.

Howler Monkeys Have Smaller Brains Than Equally Sized Spider Monkeys