24 Cognitive Biases in Decision Making, Listed and Defined

Key points from the infographic

ET Graphics lists 24 cognitive biases around a drawing of the brain, under the title “The Fault Within Us”.
Its introduction says experts have identified more than 180 cognitive biases that warp our sense of what is real.
The list runs from anchoring and confirmation bias to the sunk cost fallacy and the spotlight effect.
Two quotes sit among the biases, from Richard Feynman (“you must not fool yourself”) and Mark Twain.
The graphic credits the list to School of Thought and its source line to Visual Capitalist.

The 24 cognitive biases in text

Each definition is as written on the graphic.

Bias	Definition on the graphic
Anchoring	The first thing you judge influences your judgement of all that follows
Confirmation bias	You favour things that confirm your existing beliefs
Declinism	You remember the past as better than it was, and expect the future to be worse than it will likely be
Just world hypothesis	Your preference for a just world makes you presume that it exists
Framing effect	You allow yourself to be unduly influenced by context and delivery
In-group bias	You unfairly favour those who belong to your group
Fundamental attribution error	You judge others on their character, but yourself on the situation
Placebo effect	If you believe you’re taking medicine it can sometimes “work” even if it’s fake
Halo effect	How much you like someone, or how attractive they are, influences your other judgements of them
Bystander effect	You presume someone else is going to do something in an emergency situation
Reactance	You’d rather do the opposite of what someone is trying to make you do
Belief bias	If a conclusion supports your existing beliefs, you’ll rationalise anything that supports it
Backfire effect	When your core beliefs are challenged, it can cause you to believe even more strongly
Dunning-Kruger effect	The more you know, the less confident you’re likely to be
Curse of knowledge	Once you understand something you presume it to be obvious to everyone
Groupthink	You let the social dynamics of a group situation override the best outcomes
Negativity bias	You allow negative things to disproportionately influence your thinking
Optimism bias	You overestimate the likelihood of positive outcomes
Sunk cost fallacy	You irrationally cling to things that have already cost you something
Barnum effect	You see personal specifics in vague statements by filling in the gaps
Availability heuristic	Your judgements are influenced by what springs most easily to mind
Self-serving bias	You believe your failures are due to external factors, yet you’re personally responsible for your successes
Pessimism bias	You overestimate the likelihood of negative outcomes
Spotlight effect	You overestimate how much people notice how you look and act

The two quotes read: “The first principle is that you must not fool yourself, and you are the easiest person to fool” (Richard Feynman) and “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so” (Mark Twain).

How cognitive biases affect decision making

A cognitive bias is a systematic pattern of deviation from the norm or from rationality in judgement [3]. Some biases come from mental shortcuts, called heuristics, which allow faster decisions when speed matters more than accuracy, and others are a by-product of limits on how much the brain can process [3]. Anchoring is a well studied example. Amos Tversky and Daniel Kahneman described it in 1974 as a heuristic people use when making estimates under uncertainty [5].

The World Economic Forum, republishing the Visual Capitalist version of this list, notes that there is no simple way around these instincts, but that understanding the specific mistakes we make, and why, is one thing we can do [2]. School of Thought, the non-profit behind the original list, offers the 24 biases as free posters and cards to help people spot them [1].

Notes on this infographic

The Dunning-Kruger line is a simplification. The effect, formalised by David Dunning and Justin Kruger in 1999, is that people with low skill in an area tend to greatly overestimate their competence in it [4].
In the Feynman quote the graphic uses a dash after “fool yourself”. We show it as a comma.
The figure of more than 180 cognitive biases matches the Visual Capitalist article republished by the World Economic Forum [2].
The graphic is an Economic Times (ET Graphics) version of School of Thought’s “24 cognitive biases” poster, which Visual Capitalist also published [2].

Questions about cognitive biases

What is a cognitive bias?

A systematic pattern of deviation from the norm or from rationality in judgement [3]. The graphic’s introduction calls them mental mistakes that may lead to inaccurate judgements.

What is anchoring bias?

On the graphic, anchoring means the first thing you judge influences your judgement of all that follows. Tversky and Kahneman described it in 1974 as a heuristic used to make estimates under uncertainty [5].

Is confirmation bias a heuristic?

The two terms overlap. A heuristic is a mental shortcut, and some cognitive biases are the result of such shortcuts [3]. The graphic lists confirmation bias as favouring things that confirm your existing beliefs, and lists the availability heuristic as a separate entry.