Intelligence Wasn’t In Their Genes

(One of my tasks is testing DNA samples using an electrical current running through a gel in an acrylic box. The electrodes on the box and the wires that you plug in are color-coded black and red for negative and positive, just like on a car battery. If you plug them in the wrong way, you lose your samples.)

Me: “How come the red and black electrodes are labelled ‘RED’ and ‘BLACK’ in writing?”

Scientist: “One of our previous techs wasn’t as smart as you.”