Which of the following is true of research on insight?

A) Researchers have found that only human beings are capable of insight learning.
B) Researchers have found support for the existence of both human and animal insight learning.
C) Researchers have found that apes are capable of insight only after being taught this by humans.
D) Researchers have proven that all creatures, even one-celled organisms such as the amoeba, are capable of insight learning.

Research on insight learning has found support for the existence of both human and animal insight learning, suggesting that animals are also capable of solving problems through sudden realization and understanding. Studies have shown that various species of animals, including apes, birds, and rodents, have demonstrated insight learning without being explicitly taught by humans. However, there is debate and ongoing research regarding the extent of animals' ability to experience insight compared to humans. Option A, C, and D are incorrect because they are either false or have no empirical support.