Let’s face it: the comments section of most news and opinion articles on the internet is terrible. The opportunity provided by new technology to respond easily and anonymously seems to have lead to an increase in the amount of vicious insults and bad language on the part of commenters (I’m proud to say the commenters on this blog are a notable exception). At Psychology Today, Dalrymple outlines two different theories to explain this phenomenon, what he calls the Romantic theory:

Those who favour the hydraulic theory of emotions – for example that there is always a certain amount of aggression to be expressed, and if it is not turned outward in some constructive fashion it will turn either inward or outward in a destructive way – would presumably think that the bile was always there and was previously expressing itself in some way even more unpleasant than these internet posts.

…and the Classical:

…those who favour the view that an appetite grows with the feeding would think that the ability and willingness to express bile will simply result in the production and expression of yet more bile. In other words, the habit of expressing your bile or your venom makes you more bilious or venomous. If you control yourself, then, your bile and venom will tend to disappear.

As you already know, TD favors the latter.