> remember that deaf-blind people exist [... ...] able to understand language
I got curious if/how deafblind people learn to communicate in the first place, if they are completely deafblind from birth. If humans can learn not just communication but language without either vision or hearing, that seems to suggest either extreme adaptability or language learning being quite decoupled from vision and hearing. From an evolutionary standpoint, I imagine that both deafness and blindness are probably uncommon enough that language learning could have explicit dependencies on both hearing and vision.
I found an old-looking video about communication with deafblind people. At the linked timestamp is a woman who is deafblind since age 2.
I got curious if/how deafblind people learn to communicate in the first place, if they are completely deafblind from birth. If humans can learn not just communication but language without either vision or hearing, that seems to suggest either extreme adaptability or language learning being quite decoupled from vision and hearing. From an evolutionary standpoint, I imagine that both deafness and blindness are probably uncommon enough that language learning could have explicit dependencies on both hearing and vision.
I found an old-looking video about communication with deafblind people. At the linked timestamp is a woman who is deafblind since age 2.
https://youtu.be/usaf3bVVvjY?t=840