Ethology

Tigers are solitary, but are also known to socialize with members of their species.  Tigers tend to hunt alone, using calculations allowing them to sneak up on their prey and attack when the moments right.  This is a sign of intelligence in the tiger.  Although tigers prefer to hunt alone, they have been known to share with others, this indicates that tigers communicate with others.  Tigers are also very emotional creatures, and show affection.  This has been seen by humans that study tigers long term, and have grown to be accepted by the tigers as one of them.  The tigers will cuddle and play with the human as if they were one of their own.  Their intelligence in hunting is beneficial to their survival since destruction of their habitats has left food sources to dwindle, hunting alone with a less chance of being detected serves as a way of survival and a higher chance of success.

Sources: http://www.tigers-world.com/; http://www.louisdorfman.com/species/tigers.html;