The weight equals quality thing is probably related to the use of dense metals as money since the dawn of history. Maybe it's a quirk of human psychology that c

The weight equals quality thing is probably related to the use of dense metals as money since the dawn of history. Maybe it's a quirk of human psychology that caused us to choose dense metals or maybe it's the choice of dense metals that persists as the weight/quality association. With plastics, I think there are subtle differences in flex & texture that can clue you in you quality.