What are the four sociological concepts in "Titanic" and how?
There are various types of sociological concepts addressed in "Titanic". Four that most play a part in the movie are those concerning gender, social class and ethnic inequalities, and the question of "nature versus nurture".
Gender: Rose and her mother have been left destitute by her father's death. Their only hope for "survival" is to marry Rose to a wealthy husband. Her fiance, Cal, makes it quite clear that Rose is to reflect well on him, and that he is capable of violence towards her if she does not comply.
Social class: Titanic is so stratified that the third class passengers do not mingle with first, although the first class dogs come to their deck to defecate. When the boat is sinking, despite claims of "women and children first", third class passengers are kept locked below.
Ethnicity: People who do not speak English--and speak it "properly"--are not treated well. There are no signs in any other languages to help the passengers navigate the ship. The Irish built the ship, but it is owned by the English.
Nature versus Nurture: When Jack attends the first class dinner party in a borrowed tux, Cal smirks that he "almost looks like a gentleman." It is assumed by some of the first class passengers that they deserve their money, despite the fact that most were born with it. The poor are looked down as simply for not having money; they are somehow suspect simply for being poor. The movie makes the point that Jack, poor man though he is, is a much better human than Cal.
You could make more connections with this movie to different types of sociological concepts.