Coin tosses can be easily rigged: study

December 7, 2009

The ubiquitous coin toss is not so random after all, and can easily be manipulated to turn up heads, or tails, a Canadian study has found.

Used for centuries to settle feuds, start sporting matches, decide an uncertain course of action, and even as a randomization tool in some research studies, tosses were thought to be impartial arbiters.

Not so, say researchers at the University of British Columbia in westernmost Canada who found that the outcome of a can actually be influenced with minimal training.

They asked 13 ear, throat and mouth (otolaryngology) residents in Vancouver to each flip a coin 300 times to see if they could bring up heads.

All of the participants achieved more heads than tails, with 7 of the 13 coming up with "significantly more heads" than tails, said the study published in the current December 7 issue of the (CMAJ).

One of the participants was able to achieve heads 68 percent of the time.

Success depended on how high a coin was tossed, how quickly it was tossed it, how many times it was spun and how it was caught.

"This study shows that when participants are given simple instructions about how to manipulate the toss of a coin and only a few minutes to practice this technique, more than half can significantly manipulate the outcome," the researchers wrote.

The study was included in the CMAJ's annual Christmas holiday review of offbeat research.

Other CMAJ highlighted studies found:

-- a link between rain and medical school admissions. Students interviewed on rainy days received a one-percent lower score on admissions tests than those on sunny days, suggesting mood plays a part in selection;

-- quarantine and cure would only delay the inevitable spread of a zombie outbreak. A was created for just such an unlikely occurrence;

-- and public health officials must come up with scarier names for viruses in order to frighten people into taking preventive health measures to curb epidemics.

"H1N1 sounds like the name of an income tax form or a robot that might hang out with R2D2 in Star Wars," said researchers. "Compare this to the Black Death.

"If public health physicians want people to live, they must learn how to scare them to death."

(c) 2009 AFP

3.5 /5 (10 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

jerryd
Dec 07, 2009

Rank: 3 / 5 (2)
The rates they claim are in the probability range. Notice 50% achieve higher rates of head which means 50% would hit tails too.

The 7 out of 13 just means one or the other had to be ahead as it was an odd number.
x646d63
Dec 07, 2009

Rank: 5 / 5 (2)
@jerryd, I don't think you read it correctly:

All of the participants achieved more heads than tails, with 7 of the 13 coming up with "significantly more heads" than tails


It's unlikely that chance would have all 13 flip more heads than tails, but that was the case.
Adrianrain
Dec 07, 2009

Rank: 3 / 5 (2)
I use a trick all the time and it works for me. If i need to flip a coin and i want it to be heads for example. I will keep flipping it till i get two tails in a row then I will go out to where I have to go and flip it again. Three tails in a row is hard to get but two tails followed by a heads seems easier.
jonnyboy
Dec 07, 2009

Rank: 5 / 5 (1)
Adrainrain. instead you should be trying to flip heads until you figure out what speed and how high to toss it. What you are describing would work about as well as spinning around in a circle twice to the right and then once back to the left.
axemaster
Dec 08, 2009

Rank: 5 / 5 (1)
Adrainrain... each flip is independent of the others, so no matter what you do beforehand, that 3rd flip will always be 50/50 chance.
BetaSki
Dec 08, 2009

Rank: not rated yet
This really is not very shocking, although it may confirm previously simply paranoid fueders. Of course, the standard procedure for preventing this kind of tampering is the "call it in the air" method.
ennemkay
Dec 08, 2009

Rank: not rated yet
awesome study. the best technique: the two-headed coin. i think adrianrain was joking?
KBK
Dec 08, 2009

Rank: not rated yet
It is a physical system with input from the, ur, eh.....tosser. Physical input that, for the larger part, becomes the entire energy input.

Furthermore, the termination of the 'game' or toss, is controlled by the person initiating the entire physical aspect of energy input (begin)to reach the conclusion of the 'toss'(end).

Therefore it ~CAN~ be successfully 'gamed', or altered from any random character.

I've known this for years. And my personal best is heads 168 times in a row. Not short tosses or low energy input with low numbers of revolutions. About2 feet in height on average and a fast spin of about1.5 seconds in length. It's all in the initial energy input..and the TIMING of the toss. Listen to the 'ring' of the coin..it has to be ~Just right~. use the same coin every time.

As for timing issues, the best drummer, on record, using a click track, can come down on the beat REPEATEDLY..at 100,000th of a second. He's known as the 'human metronome'. Look it up.
ricarguy
Dec 08, 2009

Rank: 5 / 5 (1)
I like the mathematical model about the zombie outbreak the best. One can create a model to show most anything you want. Just ask Michael Mann. LOL
bfast
Dec 08, 2009

Rank: not rated yet
Jonnyboy, "instead you should be trying to flip heads until you figure out what speed and how high to toss it."

BetaSki, "Of course, the standard procedure for preventing this kind of tampering is the "call it in the air" method".

KBK, "I've known this for years. And my personal best is heads 168 times in a row. Not short tosses or low energy input with low numbers of revolutions. About2 feet in height on average and a fast spin of about1.5 seconds in length. It's all in the initial energy input..and the TIMING of the toss. Listen to the 'ring' of the coin..it has to be ~Just right~. use the same coin every time."

KBK, I don't buy it.

That said, I have a 100% call success rate. You can call it in the air, and I still will produce the opposite of your call. I flip the coin in the air, snatch it out of the air, and place it on my opposite forearm. Thats how I was always taught to do a coin toss. Once I have grabbed the coin, I feel it with my finger, and present my choice
Yes
Dec 08, 2009

Rank: not rated yet
Students interviewed on rainy days received a one-percent lower score on admissions tests than those on sunny days, suggesting mood plays a part in selection;

1 percent out of one hundred? Now you see evidence that the writers of this article do not understand much about statistics. Unless they had a million test persons, this says nothing. And even then I would say 5% for drawing conclusions
qwelkjhe
Dec 09, 2009

Rank: not rated yet
http://en.wikiped...el_Bluth

^ That's your human metronome. Pretty silly.
Rank 3.5 /5 (10 votes)
Relevant PhysicsForums posts

More news stories

A frank discussion of the power law and linking correlation to causation

(PhysOrg.com) -- Michael Stumpf a mathematics professor at Imperial College in London, and Mason Porter a lecturer at Oxford have teamed together to write and publish a perspective piece in Science regarding the in ...

Other Sciences / Mathematics

created 7 hours ago | popularity 5 / 5 (2) | comments 2 | with audio podcast report

Employers feel no love for unscrupulous practice of 'service sweethearting'

A new study led by two Florida State University marketing professors finds that some frontline service employees who are rewarded for hikes in customer loyalty and satisfaction also may engage in "service ...

Other Sciences / Economics & Business

created 1 hour ago | popularity not rated yet | comments 0

The question of life in the ancient world

There’s a general feeling that we don’t get the Greeks – ancient or modern. Many, including heads of state like Angela Merkel, visibly shake their head in exasperation, rightly or wrongly, at ...

Other Sciences / Archaeology & Fossils

created 7 hours ago | popularity 1 / 5 (1) | comments 2

Sonic Cradle lands spot in TED exhibition

A Simon Fraser University graduate student project that melds music, meditation and modern technology has landed a rare spot as an exhibit at TEDActive 2012 in Palm Springs, California this month.

Other Sciences / Other

created 3 hours ago | popularity not rated yet | comments 0

Chilean miners' rescue capsule on show in London

The capsule used to rescue Chilean miners trapped underground for two months goes on display Saturday at the Science Museum in London -- the first time it has been seen in Europe.

Other Sciences / Other

created 6 hours ago | popularity not rated yet | comments 0


Human cognitive performance suffers following natural disasters, researchers find

Not surprisingly, victims of a natural disaster can experience stress and anxiety, but a new study indicates that it might also cause them to make more errors - some serious - in their daily lives. In their upcoming Human Fa ...

The power of estrogen -- male snakes attract other males

A new study has shown that boosting the estrogen levels of male garter snakes causes them to secrete the same pheromones that females use to attract suitors, and turned the males into just about the sexiest ...

New error-correcting codes guarantee the fastest possible rate of data transmission

Error-correcting codes are one of the triumphs of the digital age. They’re a way of encoding information so that it can be transmitted across a communication channel — such as an optical fiber o ...

Putting the squeeze on planets outside our solar system

(PhysOrg.com) -- Using high-powered lasers, scientists at Lawrence Livermore National Laboratory and collaborators discovered that molten magnesium silicate undergoes a phase change in the liquid state, abruptly ...

Both maternal and paternal age linked to autism

Older maternal and paternal age are jointly associated with having a child with autism, according to a recently published study led by researchers at The University of Texas Health Science Center at Houston (UTHealth).

Curry spice component may help slow prostate tumor growth

Curcumin, an active component of the Indian curry spice turmeric, may help slow down tumor growth in castration-resistant prostate cancer patients on androgen deprivation therapy (ADT), a study from researchers ...