The two concepts can seem similar, but they are different. When trying to understand the difference for the first time it can be complicated and I hope I can put it across effectively.
Cognitive distortions
These are simply ways that our mind convinces us of something that isn’t really true (Grohol, 2017). These inaccurate thoughts are usually used to reinforce negative thinking or emotions — telling ourselves things that sound rational and accurate, but really only serve to keep us feeling bad about ourselves.
For instance, a person might tell themselves, “I always fail when I try to do something new; I therefore fail at everything I try.”
Logical Fallacies
Dr. L. Kip Wheeler of Carson-Newman University in Jefferson City, TN says that these are
statements that might sound reasonable or superficially true but are actually flawed or dishonest. When readers detect them, these logical fallacies backfire by making the audience think the writer is (a) unintelligent or (b) deceptive. It is important to avoid them in your own arguments, and it is also important to be able to spot them in others' arguments so a false line of reasoning won't fool you.
One example is the Strawman Fallacy
A straw man is a common form of argument and is an informal fallacy based on giving the impression of refuting an opponent's argument, while actually refuting an argument that was not presented by that opponent. One who engages in this fallacy is said to be "attacking a straw man".
The typical straw man argument creates the illusion of having completely refuted or defeated an opponent's proposition through the covert replacement of it with a different proposition (i.e., "stand up a straw man") and the subsequent refutation of that false argument ("knock down a straw man") instead of the opponent's proposition.
Your Logical Fallacy Is — a microsite of the not-for-profit organisation schoolofthought.org — describes a strawman fallacy as
Misrepresenting someone’s argument to make it easier to attack.
After Will said that we should be nice to kittens because they’re fluffy and cute, Bill says that Will is a mean jerk for wanting to be mean to poor defenseless puppies. Everyone loudly boos Will, drowning out his protests that
this isn’t what he said at all.
Reconciling the two concepts
They can seem to merge into each other in some respects at time, especially when you look at the logical fallacy called the gambler's fallacy
Believing that ‘runs’ occur to statistically independent phenomena such as roulette wheel spins.
Red had come up six times in a row on the roulette wheel, so Jen knew that it was close to certain that black would be next up. Suffering an economic form of
natural selection with this thinking, she soon lost all of her savings. (Your Logical Fallacy Is)
You could be forgiven for thinking it may be a cognitive distortion, as in a sense it could be, but it is a logical fallacy because it is a false statement of fact which is believed to be true. If it was a pure cognitive distortion, it would be a false belief which is believed to be true. Now, again reading this back myself it can sound the same, but think of it this way.
A false statement of fact (logical fallacy) is a statement often echoed by many people around within the social circle. It is a statement believed to be true because the statement was generally made by someone else and it was believed to be true as logic dictates it to be true. If you was to think about the logic and examine the evidence, the fallacies can be brought into the open and destroyed.
A false belief (cognitive distortion) can be the same, but primarily will be a belief only held by the person holding the cognitive distortion. It is a statement believed to be true because the statement was generally built up in the mind of the person holding the cognitive distortion and it was believed to be true as past experience dictates it to be true. If logic was allowed to take over, the cognitive distortion could be destroyed in time.
How can you avoid cognitive distortions and logical fallacies within yourself?
One way you can avoid them is to apply Occam's Razor. This has been termed as
[with] other things being equal, simpler explanations are generally better than more complex ones (Wikipedia)
and this is an interpretation of William Ockham's principle:
"non sunt multiplicanda entia praeter necessitatem" [i.e., "don't multiply the agents in a theory beyond what's necessary."] (Wheeler, n.d.)
Wheeler expanded on this with an explanation and said:
to phrase it in modern terms, "Don't speculate about extra hypothetical components if you can find an explanation that is equally plausible without them." All things being equal, the simpler theory is more likely to be correct, rather than one that relies upon many hypothetical additions to the evidence already collected. (Wheeler, n.d.)
There is also Jesse Richardson (2014) who states that you need to think for yourself and not take for granted everything you are told to think. So if you combine what both William Ockham and Jessie Richardson points out, it seems you can't go far wrong.
Further Reading
Beck, A. T. (1976). Cognitive therapies and emotional disorders. New York: New American Library.
Burns, D. D. (2012). Feeling good: The new mood therapy. New York: New American Library.
Leahy, R. L. (2017). Cognitive Therapy Techniques, Second Edition: A Practitioner’s Guide. New York: Guilford Press.
McKay, M. & Fanning, P. (2016). Self-Esteem: A Proven Program of Cognitive Techniques for Assessing, Improving, and Maintaining Your Self-Esteem. New York: New Harbinger Publications.
Wheeler, L. K. (n.d.) Logical Fallacies [Online]
https://web.cn.edu/kwheeler/fallacies_list.html
References
Grohol, J. (2017). 15 Common Cognitive Distortions. Psych Central. [Online]
https://psychcentral.com/lib/15-common-cognitive-distortions
Richardson, J. (2014). How to think, not what to think TEDx Brisbane [Online]
https://www.youtube.com/watch?v=6dluwVks444
Wheeker, L. K. (n.d.). Occam's Razor: A Useful Tool in Logic [Online]
https://web.cn.edu/kwheeler/logic_occam.html
