[codetrotter]

> The easy thing to do is to ask someone “Hey, pick a random number from 1 to 10!”. The person replies “7!”.

Seven factorial is way bigger than 10. Just kidding, sorry.

But what I was actually going to say was, when I read the title of the post, before clicking through, I decided to think of a number myself and I chose the number seven. So it was fun to see that same number in the article.

10% chance in theory and in reality it’s about 25% likely for someone to pick the specific number I did. If only the odds in the lottery were this good.

Why, by the way, is it that seven is so popular?

[another-dave]

From the Reddit comments someone wrote:

"Can't have the evens, they aren't random. 1 and 9 are too close to the outside. 5 isn't random, it's right in the middle! 3 is too low. Leaving 7"

It does feel like the type of biased logic that would run through your mind in the moment — interesting to think, if we have such 'fallacies' on simple stuff, what level of blindspots do we have on more complex split-second decisions.

[aeternus]

Quite a few, anchoring is pretty interesting and can often be completely subconscious.

[DSMan195276]

I think most people (or at least those who choose 7, which I definitely used to do) associate 'randomness' with 'uniqueness', and since lots people would consider 7 to be the most 'unique' number between 1 and 10 (When considering things such as divisors and how often they are used), they pick that number as it feels the most 'random'.

[jstimpfle]

My impression is that 37 is a similar outlier if you ask for random numbers from 1-100.

[iambateman]

I was going to pick seven as well.

Personal guess for why it’s a favorite... 1. I want to signal that I’m creative. If you say “random, between 1-10” picking 5 feels amateur. 2. You said “between 1-10”, which is inclusive of 1 and 10, but you positioned me to not choose the poles with the word “between.”

3. It feels random to iterate through options and settle on one. I iterate by counting up. Since 5 is out, that leaves 6,7,8,9 in my big pile’o’random.

From there, for whatever reason 7 tends to stand out.

Crazy how predictable we are.

[kovrik]

My guess: it is all about culture. I guess asian people are more likely to choose 8 (lucky number) and avoid 4 (unlucky number).

[hackerbabz]

I think 7s feel more random because they are so uncommon in normal life. We want to avoid multiplying or dividing by 7 whenever possible. Imagine if "a dozen" were 7 instead of 12.

[earenndil]

We see 7 all the time, though, in a week.

[sophiebits]

It's large and prime, so it feels less "round".

[pvinis]

Haha wow!

Ok so I thought of the same. Let me think of a number before clicking.

Then I thought let me try something fancier, I know I would go around 6-8 so let’s switch it up. Let’s put the scale like 5 6 7 8 9 10 1 2 3 4 5 in my mind. Ok now let’s pick from a weird place, like the first half, say the middle of it. What’s that number. Oh it’s 7. I arrived to the same number while trying not to. Different kind of “randomness” I guess.

Humans are weird! :p

[TheAceOfHearts]

This past week I was reading Neverwhere, by Neil Gaiman which has the same interaction:

> "Now me," said Mr. Vandemar. "What number am I thinking of?"

> "I beg your pardon?"

> "What number am I thinking of?" repeated Mr. Vandemar. "It's between one and a lot," he added, helpfully.

> "Seven," said the marquis. Mr. Vandemar nodded, impressed.

When I encountered the question the first number that popped into my head was also seven. This was immediately followed by the thought that if I were the one picking a number I should explicitly avoid seven. Does this question and answer pair give anyone else a strong feeling of déjà vu? I think this interaction is a meme [0].

It's also interesting that most people will limit their choice to a (whole number | positive integer). The best choice is probably an irrational number like the square root of two (√2) or pi (π). Although those are still relatively predictable since most people would probably make their selection from the small set of well-known irrational numbers, so you should go one step further and add to or multiply the value.

[0] https://en.wikipedia.org/wiki/Meme

[gizmo686]

Your best choice is probably to stick with rationals, and just list off an arbitrary number of digits to the right of the decimal.

[dwild]

I tried that once with 2 friends, I asked them to think of a number between 1 and 10 and I then asked if it was 7 and they both were amazed :).

[eridius]

AIUI 3 is the most common if you ask someone to pick between 1 and 5.

I was actually surprised to see 3 wasn't the second-most-common for a number from 1 to 10.

[cheerlessbog]

Think of a vegetable. I predict you think of a carrot.

[dmurray]

Think of a number between 1 and 10. Multiply it by 9. Add the digits of that number. Subtract 5. Convert it to a letter using A = 1, B = 2, ...). Think of a country beginning with that letter. Take the second letter of the country. Think of an animal beginning with the new letter.

I predict you thought of (rot13) Ryrcunag.

Not exactly the same trick, and not guaranteed to work, but this one impressed me at a young age.

[cheerlessbog]

It works because there are remarkably few country names starting with D that don't start with DE. And everyone picks the same E.

Now try asking for an animal whose name starts with U.

[user17843]

woah, I thought of seven too, before reading the article or the comments.