Science of Doubt: The Left-Hand Experiment

How your tools might kill your confidence?

In 2003, researchers asked their students to write down their BEST or WORST qualities.

👨‍🔬

“It’s a graphology study,” they said.

(it wasn’t)

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They asked some students to write with their dominant hand.

So right hand for right-handers.

And they asked other students to write with their non-dominant hand.

So left hand for right-handers.

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Once they were done, the researchers asked each student to rate how confident they were about the qualities they just wrote down.

For example:

𝐼 𝒶𝓂 𝑔𝑜𝑜𝒹 𝒶𝓉 𝓌𝓇𝒾𝓉𝒾𝓃𝑔 𝒸𝑜𝒹𝑒. 𝐼’𝓂 7𝟢% 𝓈𝓊𝓇𝑒 𝒶𝒷𝑜𝓊𝓉 𝓉𝒽𝒾𝓈.

𝐼 𝒶𝓂 𝒷𝒶𝒹 𝒶𝓉 𝓈𝓅𝑜𝓇𝓉𝓈. 𝐼’𝓂 𝟫𝟢% 𝓈𝓊𝓇𝑒 𝒶𝒷𝑜𝓊𝓉 𝓉𝒽𝒾𝓈.

ᵢ ₐₘ gₒₒd ₐₜ dᵣₐwᵢₙg. ᵢ’ₘ 5₀% ₛᵤᵣₑ ₐbₒᵤₜ ₜₕᵢₛ.

ᵢ ₐₘ bₐd ₐₜ ₗₑₐdᵢₙg ₐ ₜₑₐₘ. ᵢ’ₘ 4₀% ₛᵤᵣₑ ₐbₒᵤₜ ₜₕᵢₛ.

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The researchers had a pile of self-evaluation scorecards.

Some were written “badly”; others were written correctly.

Can you guess what they found?

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People using their dominant hand were more confident about their thoughts!

(for positive AND negative thoughts).

I find the idea that “simply” using the wrong hand can change how you perceive yourself to be… astounding.

So here is a question for you:

🧰 What might be the impact of your tools on how confident you are about your work?

📜 Source:

Briñol P, Petty RE. Overt head movements and persuasion: a self-validation analysis. J Pers Soc Psychol. 2003 Jun;84(6):1123-39.

doi: 10.1037/0022-3514.84.6.1123. PMID: 12793580.