I think the only property humans consider special in themselves are emotions. I have the following thesis. In evolution, exact pattern matching is computationally expensive. Just as I know my mother regardless of her clothes, hairstyle, her aging face, the match isn't exact. But brain uses heuristics to pump up 89 percent match to 100 percent match. This saves computational resources. These heuristics are what we call emotions. When snake like object appears in visual field, emotional heuristic pumps up slight resemblance to generate fear response. Analytical observation would take too much time. That's why emotions appear pre rational. Capgras syndrome shows when emotional heuristic malfunctions. Visual recognition is intact. But emotional heuristic which pumps up recognition score malfunctions. That's why patient recognises face but feels it's an imposter. These arguments prove emotions are mere computational shortcuts.