Illustrator: Lines are assigned the same line weight, but still look different

I have two different line segments that I have assigned the same numerical lineweight to in the properties tab.  However, these line weights visually look very different, even when exported as a PDF.  How do I make these line weights look the same?

I am discussing the line weights on the person.  You can see that the line weights look the same when zoomed into the image, but the line on the arm looks much thicker when zoomed out.  The lines have the same numerical value