Here's a breakdown of the arguments:
Arguments for Koko's understanding:
* Impressive Sign Language Use: Koko demonstrated a remarkable ability to use sign language, producing thousands of signs, combining them into simple sentences, and even creating new signs.
* Contextual Use: Her use of signs often appeared to be context-dependent, suggesting she was not just mimicking but understanding the meaning behind them.
* Emotional Expression: Koko seemed to use signs to express her emotions and thoughts, including affection, frustration, and even humor.
Arguments against Koko's understanding:
* Lack of Complexity: Koko's language abilities were limited compared to human language. She rarely used complex grammatical structures or abstract concepts.
* Possibility of Mimicry: Some argue that her sign language use could be attributed to mimicry and reinforcement training rather than true understanding.
* Difficulty in Measuring True Understanding: It's impossible to know for sure what is happening inside another being's mind. Koko's ability to use sign language may have been impressive, but it doesn't necessarily translate to "understanding" in the same way a human does.
Conclusion:
While Koko's abilities were undoubtedly remarkable, the question of whether she truly "understood" sign language remains a matter of debate. Her impressive communication skills cannot be dismissed, but the complexity of language and the challenges in understanding another species' mind make it difficult to draw definitive conclusions.
Important Note: Koko's story highlights the complex relationship between humans and animals, and the ethical questions involved in studying animal communication.