Final answer:
The statement regarding the numerical grasp of African grey parrots being comparable to aquatic mammals, chimpanzees, and small children is false. The Harlows' study showed that rhesus monkeys prioritize social comfort over food. Primates like chimpanzees exhibit complex behaviors due to their brain structure, including tool use and sophisticated social structures.
Step-by-step explanation:
According to Millburn, the statement that African grey parrots' grasp of numbers is comparable to that of aquatic mammals, chimpanzees, and small children (think of those between four and six years) is false (b). African grey parrots are known for their cognitive abilities, especially in communication and problem-solving, but there is no specific mention in the provided references that compares their numerical understanding directly to those groups. However, the references do acknowledge the intelligence and social behaviors of primates, such as chimpanzees, and their ability to use tools for various purposes, which is indicative of higher cognitive functions beyond numerical understanding.
The Harlows' study on rhesus monkeys showed that social comfort is more important than food (d). This profound study revealed that infant monkeys valued the comfort and security provided by a 'surrogate mother' made of soft cloth over a wire mother that provided food, underlining the importance of social interactions for normal development.
In a broader perspective, primates, including the chimpanzee, have been characterized by a larger brain-to-body ratio and increased cortical folding which is associated with complex behaviors. This underscores the advanced cognitive capabilities that can be found amongst primates, such as the usage of tools and social behaviors.