I've seen a previous ID/marketing study on this before. I may make some mistakes in the description, as I was introduced to this study about 5 years ago.
Basically they took 10 "average US consumers" and gave them $X dollars. They had to go into a single Home Depot, all the same one, and spend that $X on a power drill. If there was money left over, they could keep it. They could also keep the power drill for life. They were just given the $ and told to shop smart, picking the best possible power drill option.
90+% of them picked the heaviest power drill. This drill had the worst warranty, worst battery life, worst power output, it was an off-name, etc, etc. Basically, it was the worst power drill there. Regardless of all other features/warranty/claims/marketing, they chose the heaviest, because it "felt" the best.
The simple answer to this is...
Heavy things usually don't break. It is a hardwired concept in our human minds. What is stronger, a sapling or a redwood tree? What is stronger, a giant boulder, or a pebble? It may not always be correct. But if you answer gut-reaction and honestly to these questions, you know the answer is "the bigger one".
Go back 10 million years. If you were choosing a club used for hunting and defense, do you pick the heavy stick, or the lightweight stick? Remember, you don't have the intellectual thought you have today to determine that the lighter one will be easier to carry. So, you pick the heavy one.
There is also the fact that products made from the late 1800s up until post WW2 (even later of course) relied heavily manufacturing to be superior to their competition. A big solid metal flashlight was going to be better than a lighter weight flashlight, because they both likely used the same overall materials and overall manufacturing processes. But the heavier one was heavier because it had more metal, therefore making it stronger and less prone to breaking.