The general consensus on the internet (if you Google around, visit forums, Yahoo! answers, some from people who claim to work in the laundering business) is that high dryer heat causes clothes to shrink.
But I recently came across this Washington Post article from an 'expert' that got me wondering if that's true.
The first myth debunked: Dryer heat does not shrink garments. After all, as Ottusch pointed out, a hot iron does not shrink clothes; in fact, the heat and pressure of the iron cause the garment to stretch out. Rather, she said, shrinkage is caused by the tumbling action as the garments hit the sides of the dryer.
Could anybody verify which is true? It seems like someone with some science knowledge might know the answer to this, since there may not be many articles studying the effects of heat on clothing shrinkage.