It's not known for sure why they went extinct and the extent of their cognitive abilities. It's also only one example. Another might be Europeans coming to the

It's not known for sure why they went extinct and the extent of their cognitive abilities. It's also only one example. Another might be Europeans coming to the Americas (with more deadly technology and infections diseases, not smarter). Or humans being super predators. We don't know what advanced alien life would be like. Or what AI might become. There's lots of possibilities. Sagan's Contact and The Culture are on on one end, with The Dark Forest and Skynet being on the other.