Propaganda and fallacies.

Are cognitive biases also errors in logical thought? Or are cognitive biases an error in judgment?

I submitted a reply previously, but it seems to have gotten lost in the fallacyverse. I'll try again.

A cognitive bias is a defect, or deviation, in rationality. Effectively we use suboptimal reasoning and it can affect our decision making and judgement. The difference between a bias and a logical fallacy is that fallacies are logical errors in argumentation. So if it's not used in an argument, it's not really a fallacy.

Examples:

Alice sees her friends Bob, Carol and David all got the new Breezy sneakers. As a result, she goes online and orders a pair for herself. This is the Bandwagon Effect - a cognitive bias.

Alice is now deciding whether to order the new Breezy II sneakers. Emily asks her why she thinks they're good, to which Alice replies, "because everyone else thinks they're good." This is the Appeal to Popularity - a logical fallacy.

So biases are errors in logical thought, which can create errors in judgement. Alice may hop on the bandwagon and buy the sneakers, but later find out they're a poor fit, don't last, or just don't feel right for her. She made an error in judgement, based on an error in thinking.

Nice example! 

"The difference between a bias and a logical fallacy is that fallacies are logical errors in argumentation. So if it's not used in an argument, it's not really a fallacy."

What about the Stereotyping (the fallacy) which is based on a statement or a claim rather than an argument? 

Stereotyping becomes fallacious when used as a justification. For example:

"French people are great at kissing.  Julie is French.  Get me a date!"

Julie is assumed to be good at kissing because of her French heritage. A stereotype - that the French are good kissers - is used as a justification for dating her, hence we have a Sweeping Generalization.

"Jews control the banks" is a stereotype.

It seems that according to the Stereotyping (the fallacy) a fallacy doesn't have to be an argument, but can be a statement or a claim. 

"Atheists are morally bankrupt."

"Explanation: This isn’t an argument, but just an assertion, one not even based on any kind of facts.  Stereotypes such as these usually arise from prejudice, ignorance, jealousy, or even hatred."

I suggest you review the whole introduction to logical fallacies in Bo's book. Here is a snippet (emphasis mine): 

"What's the Difference Between Logical Fallacies and Cognitive Biases?
In the early 1970s, two behavioral researchers, Daniel Kahneman and Amos Tversky pioneered the field of behavioral economics through their work with cognitive biases and heuristics, which like logical fallacies, deal with errors in reasoning. The main difference, however, is that logical fallacies require an argument whereas cognitive biases and heuristics (mental shortcuts) refer to our default pattern of thinking. Sometimes there is crossover. Logical fallacies can be the result of a cognitive bias, but having biases (which we all do) does not mean that we have to commit logical fallacies. Consider the bandwagon effect, a cognitive bias that demonstrates the tendency to believe things because many other people believe them. This cognitive bias can be found in the logical fallacy, appeal to popularity.

Everybody is doing X.
Therefore, X must be the right thing to do.

The cognitive bias is the main reason we commit this fallacy. However, if we just started working at a soup kitchen because all of our friends were working there, this wouldn’t be a logical fallacy, although the bandwagon effect would be behind our behavior. The appeal to popularity is a fallacy because it applies to an argument.

I would say that more often than not, cognitive biases do not lead to logical fallacies. This is because cognitive biases are largely unconscious processes that bypass reason, and the mere exercise of consciously evaluating an argument often causes us to counteract the bias."

Very good point!

If I were to stop and think about why I'm going to the soup kitchen, I would probably realise that "because my friends are working there" isn't a good enough reason.