The human brain is significantly larger than that of all other animals, including the animals that are similar to us in size. A recent study by Harvard scientists did show that some animals can think in ways that were once considered to be unique to humans, such as having an episodic memory.
However, the study would further show that there are still cognitive rifts between humans and other highly intelligent animals. For instance, other animals may be able to use a specific solution to solve a specific problem; however, only humans are able to apply solutions to new situations or to solve different kinds of problems.
Another example is that other animals, such as chimpanzees, have the ability to use simple tools. But only humans can combine materials to create a tool with different functions.