I've been reading about the Dunning-Kruger effect recently. It's a theory put foward by psychologists of that name which basically states that less intelligent people overestimate their abilities because they're not bright enough to spot their mistakes while conversely more intelligent people underestimate their abilities for the opposite reason.
The effect can be seen in lots of different fields but one that strikes me as especially apt is beer writing. On the one hand are people paid to write on beer who proclaim themselves "one of the world's leading beer writers" or "an internationally known authority on beer" while recycling myths or just making things up; on the other, unpaid bloggers like Ron Pattinson at Shut Up about Barclay Perkins and Martyn Cornell at Zythophile whose writing is based on extensive research in their spare time and rigorous analysis of primary sources, correcting their own misconceptions and overturning orthodox opinion where necessary.
The idea behind the Dunning-Kruger effect isn't a new one - I suppose it's a variant of the saying "An empty vessel makes most noise" - but it's good to have a scientific label to stick on it.