Insights

In-depth guides to each test: what it measures, what the research says, and how to read your score.

• CRT · 9 min read

  The Cognitive Reflection Test: why smart people fall for simple traps

  What the Cognitive Reflection Test and the bat-and-ball problem really measure, what scores predict, and the debates about numeracy and familiarity.

• DT · 8 min read

  The Dark Triad, explained without the hype

  What Machiavellianism, narcissism and psychopathy really mean in personality research, how Dark Triad tests work, and what a score can and cannot tell you.

• EQ · 9 min read

  Emotional intelligence: what the science actually says

  Where EQ comes from, what it does and does not predict, whether it can be trained, and how our free emotional intelligence test works.

• FQ · 9 min read

  Your financial mind: literacy, patience and loss aversion

  What a financial literacy quiz and a loss aversion test really measure: the Big Three questions, discounting, prospect theory and the debates around them.

• 16T · 8 min read

  16 personality types vs the Big Five: what your type really tells you

  Where the 16 personality types come from, why researchers prefer the Big Five, and how to read a free type test's letters and percentiles.

• IQ-Q · 9 min read

  What is fluid intelligence, and how is IQ measured?

  What fluid intelligence is, how matrix puzzles measure it, what IQ scores like 100 or 130 mean, and what a free online IQ test can and cannot tell you.

A field guide to the mental shortcuts that trip everyone up — one short, practical page each.

• Anchoring effect

  The first number we see tends to drag our later estimates toward it.

• Availability heuristic

  We judge how likely something is by how easily examples spring to mind.

• Base-rate neglect

  We focus on vivid details of a case and forget how common the outcome is overall.

• Confirmation bias

  We tend to look for, and believe, evidence that fits what we already think.

• Conjunction fallacy

  We rate a detailed story as more likely than a simpler one, even though logically it can't be.

• Endowment effect

  Owning something can make it seem worth more than we would have paid to get it.

• Framing effect

  The same facts can lead to different choices depending on how they are worded.

• Fundamental attribution error

  We tend to explain other people's actions by who they are and underrate the situation they are in.

• Gambler's fallacy

  We expect random streaks to 'even out', as if chance had a memory.

• Halo effect

  One strong impression of someone spills over into how we judge their other, unrelated qualities.

• Hindsight bias

  Once we know how something turned out, we tend to believe we could have predicted it.

• Illusion of control

  We often feel we can steer outcomes that are mostly down to luck, especially when we get to make choices.

• Loss aversion

  Losing something tends to feel worse than gaining the same thing feels good.

• Negativity bias

  Bad experiences and information tend to affect us more strongly than good ones of the same size.

• Overconfidence

  We often think we know more, or do better, than we actually do.

• Planning fallacy

  We expect our own tasks to go faster and smoother than similar tasks usually do.

• Present bias

  We make patient plans for the future, then choose the easy option when the future becomes now.

• Status quo bias

  We tend to stick with the current option or the default, simply because it is already there.

• Sunk cost fallacy

  We keep going with something because of what we've already put in.

• Survivorship bias

  We study the cases that survived and forget the ones that dropped out, so success looks easier and more predictable.