

Discover more from Mental Models Weekly
Warren Buffet famously quippedââââdonât ask the barber if you need a haircut.â
Want to know why?
Itâs called The Law of the Instrument. Let me explainâŚ
What is The Law of the Instrument?
The law of the instrument is a cognitive bias in which people tend to rely too heavily on the same âtoolâ for every purpose. We have a tendency to rely on the tool that is familiar to us. Like Buffet's barber holding his or her scissors thinking you need a haircut.
When Buffet said âdonât ask the barber if you need a haircut", he elaborated:
Be careful who you ask for advice as salespeopleâs job is to sell you on what theyâre selling. Iâve made this mistake many times, asking the salesperson if he thinks what heâs selling is worth it. Theyâll always say yes.Â
Why is this interesting?
It's great to keep this law in mind when consulting any kind of specialist. The law of the instrument extends further into higher risk areas - beyond just the barber. It applies broadly when dealing with specialists of any kind.
Specialists can include doctors, lawyers, engineers, architects, mechanics and so on. Their framing, and often their incentives are not always totally aligned with yours.
Iâll leave you with this wise advice via Nassim Taleb:
The psychologist Gerd Gigerenzer has a simple heuristic. Never ask the doctor what you should do. Ask him what he would do if he were in your place. You would be surprised at the difference.
Want to go deeper?
đ Read my extended post Don't Ask the Barber if you Need a Haircut, in which I argue the merits of becoming more of a generalist in order to manage your specialist.
đ The French have a concept called dĂŠformation professionnelle, which is our tendency to assess situations from the perspective of our profession.Â
đ Similarly, the Einstellung effect occurs when "a repeated solution to old problems is applied to a new problem even though a more appropriate response is available".
đ¤ Maybe itâs most easily remembered with a little latin â caveat emptor â buyer beware.
đ¨ Of course I have to include the classic quote, often attributed to Abraham Maslow:
I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail
đ§  Build your latticework! Revisit related mental models:
Cognitive Reframing đźď¸
Got comments?
đ§ Reply to this email
đŚ Tweet @juliaclavien
đď¸ Connect with me
đ Enjoy this newsletter? I'd love you to share it with a friend!