The GUI you see is not the GUI you "want" to see, it's a second ;-)
In your init()
function you create a second HumanInterface
:
HumanInterface gst = new HumanInterface();
gst.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
gst.pack();
gst.setVisible(true);
I think you probably want that (not tested):
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.pack();
this.setVisible(true);