Honetly it depends on how old they are if there like five then no if there lets say 13 our older than yea its fine you see the point i want to make is that we should sheild our children from this things in fact we should slowly expose them to it because i have found that it may expand there senes of humor,muchure them,our do nothing of importance but of cousre the shouldnt be able to do it in movie theatures only in there own home
A study surveying over 6,000 American adolescents (https://geiselmed.Dartmouth.Edu/news/2010/03/12_sargent.Shtml) reported that watching R-rated movies increases the sensation seeking tendency, which makes adolescents more prone to engage in all sorts of risky behaviours, including substance abuse. Another study (https://www.Ncbi.Nlm.Nih.Gov/pmc/articles/PMC2920486/#!Po=12.9921) analysed several different studies and found that they have linked exposure to movie smoking and adolescent smoking. The study, surveying 6,522 Americans aged 10-14 found that adolescents who watch a lot of R-rated movies are less effected by R-rated movies than those who don't watch many as they become de-sensitized, so watching an extra R-rated movie or two won't do much.
The answer is really in the picture: "Under 17 requires accompanying parent of adult guardian." Plain and simple. Children under 17 cannot watch R-rated movies by themselves in movie theaters unless they're occupied by parents or legal adults. In private at their own home, that's up to the parents, because I was allowed to watch The Breakfast Club when I was 12, but in public, in actual movie theaters, not by themselves, but with a parent/guardian as the label says.