How Confident Should You Really Be?

Introduction

Good judgement does not require perfect certainty. It requires matching your level of confidence to the strength of the evidence available. That means being highly confident when multiple, independent, direct sources point to the same conclusion, moderately confident when the evidence is suggestive but incomplete, and cautious when the evidence is weak, indirect or conflicting. This ability—often called confidence calibration—is one of the practical foundations of intellectual humility. It allows you to act before certainty while avoiding both unwarranted certainty and unnecessary hesitation. Research across psychology, decision science and medicine consistently finds that people often miscalibrate their confidence, becoming either more certain or less certain than the evidence justifies.[PMC+2The American Journal of Medicine]pmc.ncbi.nlm.nih.govPMCAn Experimental Study of Overconfidence Biases in Young DecisionThis strong alignment supports the notion that overconfidence is associated with poorer…

Rather than asking, “Am I confident?”, a better question is, “How much confidence does this evidence deserve?” That shift changes confidence from a personality trait into a judgement that can be adjusted as evidence improves or weakens.

Why confidence should have a size

Confidence is not an all-or-nothing state. It is better understood as a scale. The ideal is for your certainty to increase or decrease in proportion to the reliability, independence and relevance of the evidence supporting a claim.

A useful way to think about this is that confidence should earn its way upwards. Every increase in confidence should be backed by something concrete, such as an additional independent source, a stronger method, direct observation instead of inference, or repeated successful predictions.

Calibration researchers define good judgement as a close match between expressed confidence and actual accuracy. If someone says they are 80% confident across many comparable judgements, roughly 80% of those judgements should eventually prove correct. Perfect calibration is difficult, but it is a practical target because it reduces predictable errors in decision-making.[Wiley Online Library+2American Psychological Association]onlinelibrary.wiley.comWiley Online LibraryCalibration Feedback With the Practical Scoring Rule Does…by M Martin · 2025 · Cited by 1 — We examined the effect…

This perspective also explains why intellectual humility is not the same as constant doubt. A calibrated thinker may express very high confidence when the evidence genuinely warrants it. Humility lies in allowing confidence to track evidence rather than identity, emotion or social pressure.

Evidence types that deserve different weight

Not all evidence deserves equal confidence. Good judgement depends on recognising which forms of evidence should move your confidence substantially and which should only nudge it.

Evidence characteristicAppropriate effect on confidenceMultiple independent sources reaching the same conclusionLarge increaseDirect measurements or observationsLarger increase than indirect inferenceEvidence replicated across different settingsLarger increaseSingle anecdote or personal experienceSmall increaseClaims from interested parties with incentives to persuadeLimited increase until independently verifiedEvidence that conflicts across high-quality sourcesReduced confidence until resolved

Several practical questions help determine how much weight evidence deserves:

• How direct is it? Seeing something measured directly is generally stronger than relying on several layers of interpretation.
• How independent is it? Ten reports that all originate from the same source do not provide ten independent pieces of evidence.
• How consistent is it? Agreement across unrelated studies or observers usually deserves more confidence than isolated findings.
• How well has it survived attempts to disprove it? Claims repeatedly tested without being overturned deserve greater confidence than claims that have never faced serious scrutiny.

In evidence-based medicine, frameworks such as GRADE distinguish between stronger and weaker evidence by considering study design, consistency, directness and risk of bias. Although developed for healthcare, the underlying principle applies broadly: confidence should reflect evidence quality, not simply evidence quantity.[ResearchGate]researchgate.netCalibrate your confidence in research findings: A tutorial on…April 24, 2020 — 24 Apr 2020 — This article provides an acce…Published: April 24, 2020

Common signs of overconfidence and underconfidence

Poor calibration can fail in two directions. Most discussions focus on overconfidence, but excessive caution also reduces judgement quality.

Overconfidence

Overconfidence appears when certainty grows faster than the evidence supports. Research distinguishes several forms, including overestimating one’s performance, believing one performs better than others, or expressing unwarranted precision about uncertain conclusions.[P.J. Healy]healy.econ.ohio-state.eduMoore Healy Trouble With OverconfidenceThe Trouble With Overconfidence - P.J. HealyJune 30, 2008 — by DA Moore · 2008 · Cited by 3885 — Experimental evidence shows that re…Published: June 30, 2008

Common warning signs include:

Studies also suggest that overconfidence is often fuelled by neglecting what is unknown. People naturally pay attention to the evidence they possess while overlooking information they have not yet sought or may never have encountered.[ResearchGate]researchgate.netKnown Unknowns: A Critical Determinant of Confidence…We propose that an important determinant of judged confidence is the…

Underconfidence

Underconfidence receives less attention but can also impair thinking. Someone may hesitate to act despite strong, consistent evidence or repeatedly discount their own well-supported conclusions.

Signs include:

• Demanding impossible levels of certainty before deciding.
• Giving weak evidence and strong evidence nearly identical confidence.
• Constantly reopening settled questions without new information.
• Assuming every disagreement means the evidence is evenly balanced.

Research on calibration shows that different tasks can produce different patterns. Difficult tasks often encourage overconfidence about performance, while easier tasks sometimes produce underestimation. The goal is therefore not maximum caution but accurate calibration.[P.J. Healy]healy.econ.ohio-state.eduMoore Healy Trouble With OverconfidenceThe Trouble With Overconfidence - P.J. HealyJune 30, 2008 — by DA Moore · 2008 · Cited by 3885 — Experimental evidence shows that re…Published: June 30, 2008

A practical way to scale confidence

Instead of thinking in vague terms such as “certain” or “unsure”, deliberately tie confidence to identifiable properties of the evidence.

One practical framework is:

The precise percentages matter less than consistency. The important habit is explaining why your confidence sits where it does.

For example:

These explanations make confidence transparent and easier to revise when new evidence appears.

Updating confidence as evidence changes

Calibration is dynamic rather than fixed. New evidence should change confidence by an amount proportional to its quality.

A single weak study should rarely overturn years of consistent evidence. Equally, one well-designed experiment may substantially change confidence if previous evidence was weak or uncertain. The key is avoiding two common mistakes:

• refusing to update because changing your mind feels like admitting failure; or
• swinging from certainty to certainty whenever a new claim appears.

Intellectual humility encourages gradual adjustment rather than dramatic reversals. Confidence should move because the evidence has changed—not because the conversation, headlines or social environment have changed.

Research linking intellectual humility with metacognitive calibration suggests that people who better recognise the limits of their own knowledge tend to produce confidence judgements that more closely match their actual performance, reducing systematic overconfidence.[Taylor & Francis Online]tandfonline.comTwo studies examined whether Intellectual Humility moderates the Dunning-Kruger Effect – the tendency of those with little relative…

Confidence is a judgement, not an identity

One of the most useful distinctions is between believing strongly because the evidence is strong and believing strongly because the belief has become part of your identity.

Confidence grounded in evidence can rise or fall without threatening self-worth. Identity-based confidence resists revision because changing the belief feels personally costly.

This distinction supports the broader aim of intellectual humility. You do not need to become less decisive. Instead, become more deliberate about why you are decisive. The strongest thinkers are not those who always sound certain; they are those whose certainty consistently expands and contracts in proportion to the quality, independence and directness of the evidence before them.

Amazon book picks

Further Reading

Books and field guides related to How Confident Should You Really Be?. Use these as the next step if you want deeper reading beyond the article.

Book

Think Again

By Adam Grant

Helps readers revise confidence without drifting into indecision.

See on Amazon

Book

Superforecasting

By Philip Tetlock, Dan Gardner

Directly models matching confidence to evidence and updating views as facts change.

See on Amazon

Book

The Scout Mindset

By Julia Galef

Encourages truth-seeking, calibrated belief, and separating confidence from ego.

See on Amazon

Book

How to Measure Anything

By Douglas W. Hubbard

Shows how uncertainty can be reduced, measured, and expressed more clearly.

See on Amazon

Browse more on Amazon: Think Again Superforecasting The Scout Mindset

As an Amazon Associate I earn from qualifying purchases.

eBay marketplace picks

Marketplace Samples

Example marketplace items related to this page. Use the search link to explore similar finds on eBay.

Shop location

UsingUSA USA USAUKCanadaAustraliaIreland

Example eBay listing

Critical Thinking 2020 3 Movie Poster Art Print Fan PopCulture Nostalgic PopCult

SearcheBay.co.uk: critical thinking poster

Browse similar oneBay.co.uk

Example eBay listing

Critical Thinking 2020 2 Movie Poster Art Print Display Famous Artwork StudioDec

SearcheBay.co.uk: critical thinking poster

Browse similar oneBay.co.uk

Example eBay listing

Critical Thinking Framed Art Print Framed Wall Art Poster Canvas Print Picture

SearcheBay.co.uk: critical thinking poster

Browse similar oneBay.co.uk

Example eBay listing

Critical Thinking 2020 4 Movie Poster Art Print PopCulture Wall Memorable Exclus

SearcheBay.co.uk: critical thinking poster

Browse similar oneBay.co.uk

Browse more oneBay.co.uk

Example items shown for inspiration; availability and pricing can change. Branchoria may earn a commission if you purchase through outbound eBay links.

Endnotes

1. Source: pmc.ncbi.nlm.nih.gov
Title: PMCAn Experimental Study of Overconfidence Biases in Young Decision
Link:https://pmc.ncbi.nlm.nih.gov/articles/PMC12730000/

2. Source: onlinelibrary.wiley.com
Link:https://onlinelibrary.wiley.com/doi/full/10.1002/ffo2.199

3. Source: researchgate.net
Link:https://www.researchgate.net/publication/340889782_Calibrate_your_confidence_in_research_findings_A_tutorial_on_improving_research_methods_and_practices

Published: April 24, 2020

4. Source: healy.econ.ohio-state.edu
Title: Moore Healy Trouble With Overconfidence
Link:https://healy.econ.ohio-state.edu/papers/Moore_Healy-TroubleWithOverconfidence.pdf

Published: June 30, 2008

5. Source: researchgate.net
Link:https://www.researchgate.net/publication/322365394_Known_Unknowns_A_Critical_Determinant_of_Confidence_and_Calibration

6. Source: researchgate.net
Link:https://www.researchgate.net/publication/383853185_The_effect_of_calibration_training_on_the_calibration_of_intelligence_analysts%27_judgments

7. Source: researchgate.net
Link:https://www.researchgate.net/publication/386057594_Individual_differences_in_overconfidence_A_new_measurement_approach

8. Source: researchgate.net
Link:https://www.researchgate.net/publication/398820406_Academic_Attainment_Intellectual_Humility_and_Self-Confidence_Unpacking_the_Dunning-Kruger_Paradox_in_Higher_Education

9. Source: amjmed.com
Link:https://www.amjmed.com/article/S0002-9343%2808%2900152-6/fulltext

10. Source: tandfonline.com
Link:https://www.tandfonline.com/doi/abs/10.1080/17439760.2021.1975155

11. Source: apa.org
Link:https://www.apa.org/pubs/journals/features/xap-10-3-156.pdf

12. Source: pmc.ncbi.nlm.nih.gov
Link:https://pmc.ncbi.nlm.nih.gov/articles/PMC10535625/

13. Source: pmc.ncbi.nlm.nih.gov
Link:https://pmc.ncbi.nlm.nih.gov/articles/PMC12101119/

Additional References

14. Source: funblocks.net
Link:https://www.funblocks.net/thinking-matters/classic-mental-models/epistemic-humility

15. Source: marketing.wharton.upenn.edu
Link:https://marketing.wharton.upenn.edu/wp-content/uploads/2015/04/WALTERS-DANIELS-JMP.pdf

16. Source: semanticscholar.org
Link:https://www.semanticscholar.org/paper/Overconfident-and-unaware%3A-Intellectual-humility-of-Leman-Kurinec/1e8f011d424048105b9a37ccda95862953933dca

17. Source: novakkevin.medium.com
Link:https://novakkevin.medium.com/the-confidence-calibration-problem-why-self-assessment-fails-us-at-the-worst-possible-moments-87a6cd9ec11d

18. Source: ejmste.com
Link:https://www.ejmste.com/download/whats-about-the-calibration-between-confidence-and-accuracy-findings-in-probabilistic-problems-from-7780.pdf

19. Source: youtube.com
Link:https://www.youtube.com/watch?v=eq6SCQNQNsc

20. Source: verywellmind.com
Link:https://www.verywellmind.com/overconfidence-bias-8707133

21. Source: frontiersin.org
Link:https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2022.939949/full

22. Source: medium.com
Link:https://medium.com/%40vplevris/the-dunning-kruger-effect-why-we-think-were-smarter-than-we-are-85ae4ca86929

23. Source: philosophyetc.net
Title: Epistemic Calibration Bias and Blame-Aversion
Link:https://www.philosophyetc.net/2021/01/epistemic-calibration-bias-and-blame.html

Published: January 18, 2021