What should I say in a presentation about tattoos for sociology?

In terms of sociology, the most interesting things about
tattoos would have to do with which groups of people do or do not have
tattoos.

I would do research into the topic to confirm that
there have been changes in the groups of people who have tattoos.  I believe that
tattoos began as very much a lower class thing.  In past times, a "normal" middle class
person would never have a tattoo.  This would have been especially true of women.  Now,
tattoos seem to be quite prevalent among all classes of
people.

I would try to make a sociological argument as to
why tattoos have become more popular and why they have lost the stigma that they had as
recently as 2 or 3 decades ago.