I was taught in physical sciences that friction was proportional to weight and surface area. We were given blocks and a 'force meter' that was a bendy springy length of metal in a wooden calibrated frame. So pull blocks on a surface with the meter to measure friction. Try different surface area, stack them for multiples of weight, plot on a graph. Mine weren't coming out on a straight line. Other people noticed theres' weren't either, so they fudged their data points. I put down the honest ones. I got it 'wrong', they got it 'right'.

Of course that old myth was nonsense, my experimental method was correct, and I've felt the injustice for decades now!