Answers For [Actual Test] - Discussing Dolphin Intelligence

Lecturer: In today's lecture, we'll dive into the topic of dolphin intelligence, discussing dolphin behavior and their physical structure in an attempt to shed light on the question, how intelligent are dolphins?

Well, concerning body size, dolphin brains are among the largest in the animal kingdom, more extensive than chimpanzees, and certain species, like bottlenose dolphins, have brains even bigger than humans. However, some current tests suggest that they do not possess the same cognitive abilities as humans despite having a similar brain size. 1For instance, dolphins are often trapped in gill nets originally intended for tuna fishing. These entanglement cases have led to unnecessary injury or deaths of dolphins gradually depleting their numbers. Clearly, dolphins don't realize that they could just jump over these vertical barriers and swim to safety. 2People often mistakenly view dolphins' eternal smile as signs of intelligence and joy. Actually, this is not a facial expression at all, but a fixed design of their head. Unlike human beings with greater than 40 facial muscles, dolphins have no such powers with which to form an expression. On the other hand, small brained animals are sometimes underrated for their level of intelligence. 3Pigeons and rats are typical examples of small brain animals which can perform tasks so complex that most humans would have trouble with them. Over the last few decades, scientists have conducted countless studies on the cognitive abilities of these overlooked animals with quite surprising results. 4Pigeons are aware of their bodies when they see their reflections in the mirror. 5Pigeons are also trained under specific conditions and gradually form instinctive reactions. In an experiment in 2009, a group of 12 pigeons was given a reward like food and water every time they pecked a key on a lab table. All birds successfully performed the trick. These test results indicate that brain size is probably not the sole factor in determining intelligence. Another argument steers the attention to the correlation between intelligence and the constituents of brains rather than their sheer sizes. It's been found that dolphin brains are comprised chiefly of fatty cells, which serve as a protective barrier between the systemic blood and the extracellular environment of the central nervous system. They are also essential components of nerve cell membranes affecting problem solving skills performance.