[malloci]

The hand is to mimic that of a traffic cop. When they want you to stop, they hold up their hand to indicate that you need to stop.

It used to be that you had to know english in order to understand them as well...many of the signs used to use the words "walk" and "don't walk"

[usrbinenv]

I guess my point is that it was still confusing. It took me a day or two to acquire a reflex. It obviously doesn't matter in the long run - you just get used to it - but I wonder why would US & Canada go a different way with regards to so many small things (think turn signals on cars being red for american cars as another example)? What would be the rationale? It's as if the western hemisphere was completely cut off from the rest of the world and had no idea how others were doing things. I don't quite understand it.

[ianferrel]

>I wonder why would US & Canada go a different way with regards to so many small things (think turn signals on cars being red for american cars as another example)?

In many cases the US were the first to mass-manufacture things to some kind of standard, so the question is really: why did the rest of the world choose a different standard. Often they have a good reason (better design, maybe), but the US also has a good reason for not switching (inertia, existing tooling, people understand the existing standard).

The US was the first place that traffic light and crossing signals were installed. The reason they didn't go with the standard the rest of the world uses is that it didn't exist.

[romwell]

The curse of innovation: you might end up being stuck with it while the rest of the world learns from your mistakes.

Case in point: Ma Bell. And things like signing the credit card receipt.

[throw827474737]

> In many cases the US were the first to mass-manufacture..

Traffic lights? Not so many actually?

[zoover2020]

And standards don't adapt? To me this feels wrong and backwards

[randomdata]

They do when there is good reason, but there isn't always good reason.

In fact, a theoretically better standard could actually be worse in some situations if people are accustomed to a different standard. Imagine if America had settled on red for go and green for stop, and then tried to change the standard to match the rest of the world. It would be a calamity as some drivers continued to adhere to the old standard that they knew.

Stop signs were originally yellow, so such a change isn't unprecedented, but in that case they also contained the word STOP so the colour wasn't critical to understanding the sign. Standards can more easily change when there is backwards compatibility available. More recently, some jurisdictions have started adopting traffic light shapes (square = stop, diamond = caution, circle = go) but retain coloured lights for backwards compatibility.

[ianferrel]

They do sometimes.

Like, the WALK / DONT WALK crossing signals that were around in my youth were slowly replaced with the HAND / WALKING PERSON ones, I'm sure because they're better for people who don't read English.

But also there is a cost to change, and it's often not worth doing if the benefit from the new system or standard isn't a lot better than the old.

[greycol]

When ATMs were first implemented they would dispense money before or at the same time as giving your card back.

This resulted in premature conclusion errors. They went to the ATM to get money. They got their money so they left... forgetting their card.

When ATMs were updated they fixed the design error. Now the card popped out and had to be removed before money would dispense. This resulted in a spike of people leaving with money hanging out of the ATM because they had been trained that removing their card was the end of the task. (Which is why money now gets sucked back into the machine if it hasn't been removed fast enough).

The point of the anecdote (other than that you hire HCI experts before implementing an interface) is that implementing a new and objectively better system doesn't necessarily result in an objectively better outcome when replacing an incumbent worse system.

[creeble]

Indeed, sometimes they do and sometimes they don't.

Why doesn't the rest of the world (outside the US) have a 3rd middle brake light (CHMSL), as was mandated in the US in 1986?

My guess is because, despite measurements of ~22% crash avoidance at the time, that number turned out to be between 0% and 4% in practice. Maybe the rest of the world didn't care about 4%, or maybe they thought it was as stupid then as it turned out to be.

But the CHMSL standard in the US has refused to die.

[metabagel]

"It's as if the western hemisphere was completely cut off from the rest of the world and had no idea how others were doing things. I don't quite understand it."

Seems like you understand it fairly well. I can't speak for Canada, but the U.S. mostly ignores how other parts of the world do things.

[Lukas_Skywalker]

Since this is HN, and I'm a pedant: reflexes can't be acquired, since they are not processed by the brain, but by the spinal cord, without involvement of the brain (e.g. pulling back the hand when touching a hot surface).

What you're thinking of is called procedural memory, which helps you perform a task without being consciously aware of it (hitting a fast baseball, looking left/right when crossing a street).

[samatman]

This is quite far from being the case.

Dr. Pavlov's seminal book is generally translated as Conditioned Reflexes. Saliva in response to a bell is a reflex, and it's an acquired one.

Not falling flat on our face when we step forward is also reflexive, as is catching something thrown to us. Both are acquired through rather lengthy processes.

There are many similar examples.

[Lukas_Skywalker]

The term reflex has changed over the years.

Back in 1649, when Descartes formulated the concept of a reflex, it was used to describe lower animals, to support his notion that they were automata without a mind on their own. The word reflex originated from the "reflection" of the sensory input into a response. The physiological backgrounds were not yet known.

In the early 19th century, Hall narrowed the definition of a reflex to be a "involuntary action of a muscle or gland in response to the stimulation of a receptor neurone which does not depend on the existence of consciousness".

Sherrington, in 1904, narrowed the definition further, introducing the concept of the "reflex arc", a hardwired pathway between receptors and effector muscles.

Pavlov later did a strange thing and widened the definition, which is the source of some confusion. Nowadays, Pavlov's Conditioned Reflexes are mostly called Conditioned Responses, to avoid this exact confusion. NB: there are people arguing that conditioned is a mistranslation, and that it should mean conditional, which makes more sense in the context.

Pretty much every current publication uses the term "reflex" for involuntary, inborn responses, detected by receptors, transported to the spinal cord by afferent nerve fibers, processed there, and the motor signal sent through the efferent nerve fibers to the effector muscles. I only found the term "conditioned reflex" in papers discussing Pavlov's experiment.

[oangemangut]

:D I have a few of the "Walk" (in white) and "DON'T WALK" (in orange) signals around me in PNW.