Personhood is a big discussion topic in the future. Will machines be conscious, will robots get rights, what about intelligent gorillas and so on. But there won't be a key criteria to personhood in the future. Maybe in the beginning we will struggle with this problem, but eventually we are bound to realise that different levels of cognition-intelligence-awareness warrant different rights and obligations. Being granted personhood rights is not a binary option. Common sense dictates that for different situations we should have different solutions.