As pointed out by you, we are much apart from the animals and this has been brought about through continuous social evolution process we have undergone over eons. Our society is set apart from any ape/chimpanzees or say Dolphins due to the fact that we have evolved certain social norms which every member is obligated to follow and this is what binds us together and addresses issues related to crime & morals. The person who was giving example of the animals mentioned should know that certain species of Cranes mate for life. The more adventurous we get or to put in words of some persons 'being more closer to nature' can spell disaster for the human community as a whole and AIDS is one such example of such doomsday predictions. To sum up the issue, we need to control our emotions to bind ourselves to the Community in form of norms that are time tested and evolved over eons,