Well, that's his way of interpretation on that part, I guess. From his point of view, I can see what he means. After all, humans are only creatures that is capable of lie, to kill with evil intentions, to torture anyone with evil intentions, greedy, wars, to be vain by use God's name that they are holy people, dirty politics, etc etc...
So which is lower, really? That is debatable for some people. That's why I disagree with Steel about his comment that humans are smartest living beings on earth.
However I can see my friend's point, if you cannot accept your limits then what are you? But lower than animal? No, I don't think so... in logical sense, we are already lower than animals 
In other sense, yes you are right that we are only one who is able to pick up a pen and communicate with people but that's our limited knowledge. From what I understand by reading few articles state that dolphins can communicate with other dolphin. But again, who knows?
