I have often tried to find cognitive arguments for using body modification as piercing and/or tattoos specifically (that some religions forbade for some reasons) but never I found such arguments: I can recognize evolution based communicative logic in "looking fitted yet fertile" or "looking symmetric" (or "sharp") as "logic" for sexual attraction (based on the visual context of sexual orientation of course, which can also have a pheromonaml/vocal/tactile and tasteful contexts), but I don't recognize how piercings and/or tattoos make someone to look more fitted, fertile or symmetric/sharp (rather the contrary with symmetry) and I feel it leaves me mostly with an emotional meaning or some linguistic meaning but just these too. Does psychology explain why people use piercing/tattoos?