It must be a full moon

September 29, 2005 2:30 AM

Is there any truth to the idea that all the crazies come out during a full moon?

My mom is a nurse, and for years she has claimed she knew whether or not it was a full moon just by how crazy the patients were acting. When patients start acting nutty, (once a gentleman threw himself down the stairs in an attempt to "escape," and another was found using the sink as a toilet--both in one day) she often says, "It must be a full moon." Come sundown, she's usually right.

A few weeks ago, I met her for dinner and we were both wiped out from insane days at work. I was telling her about how my boss had clearly lost his mind, the psycho at the grocery store, and the nut that ran out in front of my car at a busy intersection. She said that patients had been acting especially weird that day and mentioned that it must have been a full moon. Sure enough, when we walked outside, we could see that it was.

Is my mom the crazy one? :-) Is it just a coincidence? If so, how did the idea originate?

posted by saucy to grab bag (43 comments total)

Do things get crazy when the moon is full?
posted by RichardP at 2:32 AM on September 29, 2005

My father is a retired police officer and he says the effect was noticeable. However, the first thing one might want to investigate is the cause-effect relationship. Is the moon causing a difference in behaviour or is it just a convenient excuse to go crazy?
posted by keijo at 4:34 AM on September 29, 2005

My understanding is that there's more crime on nights when the moon is full just because there's more light by which to commit crimes. I'm not sure if this explanation would hold in cities, since they're lit at night regardless.
posted by duck at 4:39 AM on September 29, 2005

I worked in a children's hospital and we would always mark the full moon on the calendar ... usually meant that we would not provide anything sharp to eat with during those days.
The kids would freak out and be completely "loony" for four or five days at a time.
Also, my friend's manic-depressive son tried to kill her twice -- both durn a full moon.
posted by Makebusy7 at 5:13 AM on September 29, 2005

When I worked in a group home for mentally ill people the full moon almost always made things a little more interesting. But then, we had plenty of incidents without the full moon, so it's hard to say whether we just noticed the kicked-up craziness more because we were looking for it on full moon nights.
posted by banjo_and_the_pork at 5:33 AM on September 29, 2005

I used to think it was a case of seeing a pattern you want to see, like when someone tells you women drivers are terrible, suddenly every time a woman cuts you off you are seeing the pattern falsely reinforced. And I've read all the stuff saying it's a bogus old wives tale.
But back in the days when I answered the night phones at a newspaper, I invariably could tell when the moon was full by the volume of nutjob calls. At least a dozen times over a couple of years, I looked up and said, 'damn, it must be a full moon tonight' and it always, always was. So I believe there's something to it.
posted by CunningLinguist at 5:38 AM on September 29, 2005

There's a common flaw in thinking called confirmation bias (they use this example, in fact - and explain it better than I can). It's where we remember the data that supports our theory and ignore what does not. In the example given, when there are a lot of "nutjobs", you look at the moon, see it's full, and think, "See? A full moon. Just like I thought!" But do you recall how many times there was a full moon and the crazies weren't acting up? Good example of teaching confirmation bias here.

An effect might be there, but maybe the cause is not the moon, but something like what keijo said.
posted by ObscureReferenceMan at 6:10 AM on September 29, 2005

My mom noticed it as well, while working for the DOJ. I guess a lot of folks like to call in for various reasons (aliens attacking, etc..) and the frequency of the calls always seemed to increase around full moons. I always chalked it up to the same reasons that the tides are affected by the moon, but that Straight Dope article RichardP linked buries that one.

All of the stories seem to revolve around unbalanced people though. I'm not a neurochemist, but I wonder if the extra light of the full moon might "tip" neurochemicals over an otherwise "safe" zone, for folks living on an edge, of sorts. IOW, light supresses melatonin and increases serotonin, so folks might not sleep as well at night since there is more ambient light on nights with a full moon. We'd wake up more tired and yet strangely okay about it due to the boosted serotonin. The effect per person would be minimal, but over several billion people it would probably be noticable, especially in the areas that are more often exposed to folks living on that "edge" (law enforcement, hospitals, emts, fire departments, etc..), and especially if these folks are working off of each other.

So... any neurology folks out there? Only a handful of studies have been done in the area:

"These results suggest that the seagrass rabbitfish perceives moonlight through the eye and that moonlight directly causes melatonin suppression."
posted by jwells at 6:15 AM on September 29, 2005

I have asked Korean folks here in Korea about whether they have a similar traditional understanding of the effects of a full moon. They don't.

Ghosts, now, that's another question.
posted by stavrosthewonderchicken at 6:15 AM on September 29, 2005

Trauma and the full moon: a waning theory.
By Coates W, Jehle D and Cottington E.
Division of Emergency Medicine, Allegheny General Hospital, Pittsburgh.

There exists a popular belief in the causal relationship between the moon's phase and the incidence of major trauma. In this retrospective study we reviewed 1,444 trauma victims admitted to the hospital during one calendar year. Full moons were defined as three-day periods in the 29.531-day lunar cycle, with the middle day being described in the world almanac as the full moon. Victims of violence included those patients sustaining blunt assault, gunshot wounds, and stabbings. There was no statistical difference in number of trauma admissions between the full moon, 129 patients per 36 days (mean, 3.58), and nonfull moon days, 1,315 patients per 330 days (mean, 3.98). Mortality rate, 5.4% versus 10.3%; mean Injury Severity Score, 13 versus 15; and mean length of stay, ten versus 12 days, were not significantly different during the full moon and nonfull moon days. Victims of violence were admitted at a similar frequency on full moon, 16 patients per 36 days (mean, 0.444), and nonfull moon days, 183 patients per 330 days (mean, 0.555). We conclude that the belief in the deleterious effects of the full moon on major trauma is statistically unfounded.

posted by waldo at 7:13 AM on September 29, 2005

Ditto on what Banjo and the Pork said.
posted by Pollomacho at 7:22 AM on September 29, 2005

Someone could do an interesting analysis on MetaFilter behavior and moon cycles.
posted by caddis at 7:24 AM on September 29, 2005

My dad is a chaplain in a hospital, and he does not look forward to being on call during a full moon. It's probably just a widespread case of selective memory among medical professionals.
posted by mbd1mbd1 at 7:38 AM on September 29, 2005

My understanding is that there's more crime on nights when the moon is full just because there's more light by which to commit crimes.

Well, I know if I were planning to commit some kind of crime that might involve running away through the woods, I'd want a little light to do it by. Carrying a lantern wouldn't be so good, as it would give away my position. So I might well wait for a full moon.

The experience of being outside at night with no moon is so different compared to the same thing with a full moon that I'd be amazed if there wasn't some kind of measurable effect. Unless you're in the city, yeah.

No doubt there's a whole lot of confirmation bias going on too, just to confuse things.
posted by sfenders at 7:38 AM on September 29, 2005

I can't speak to the nutjobs, but I've held a variety of dog jobs, and on three separate occasions, with entirely different people, I've said something along the lines of "seems like everyone's crazy today" (referring to the dogs, of course) to which the people replied "full moon." By the third time, I was convinced.
posted by emyd at 8:04 AM on September 29, 2005

More nails in this coffin here
posted by Neiltupper at 8:31 AM on September 29, 2005

Anyone who believes this really needs to study the Straight Dope link, confirmation theory link, and other links provided above. The full-moon belief is an entrenched part of occupational folklore, but just isn't supported by evidence.

Is it fun to think about? Yes. But it's all about the evidence.
Although you can find people very easily who will provide you piles of anecdotal experience they think supports full moon theory, it's tantamount to me saying "The earth is flat! I have lived on earth for 36 years and I can SEE it's flat. I look off to the horizon, and I don't see any curves! This shit is flat." You can believe it if you want, but you'll have to believe it by ignoring all the concrete evidence that it's a superstition.
posted by Miko at 8:32 AM on September 29, 2005

Here's another good link.
posted by Miko at 8:35 AM on September 29, 2005

...but not fast enough.
posted by Miko at 8:35 AM on September 29, 2005

Well, here's one I know is true: In the winter, in at least one place in Canada, the full moon often coincides with a larger than average number of people going cross-country skiing at night.
posted by sfenders at 8:45 AM on September 29, 2005

Anyone who believes this really needs to study the Straight Dope link

anyone who doesn't believe this needs to work night shift dealing with the public ... it is a real phenomenon

looking through these links, i notice that "people acting goofy" ... "doing strange things" ... "saying odd things to perfect strangers" ... weren't the phenomenon investigated by the debunkers ... therefore, they haven't really debunked it

keijo may be on the right track ... people may think that because it's a full moon, it's a license to be weird

another thing i've noticed ... the weeks in november when it's still a bit warm but the weather is about to get colder ... and the weeks in march where it warms up a little but spring isn't really here ... are the worst times to deal with people ... they're downright flakey

the night of jan 1 is often the worst, though ... it's bad enough on new years' eve when many are drunk ... but watch out when many are hungover ...
posted by pyramid termite at 8:54 AM on September 29, 2005

A great example of the confirmation bias at work is when you buy a new car and then immediately notice how many people are driving the same model.
posted by goethean at 8:56 AM on September 29, 2005

I lived with a first responder for four years. Generally the assaults at the local nursing home (patient on patient, yes, it was a really bizarre place) increased during the full moon, as did call volume in general. Living in a dorm with two packrats' worth of stuff to fall over when you're trying to shut the damn scanner/call radio off gives you scars to count by. ;)

It probably is just confirmation bias, but it sure seemed real at the time.
posted by Medieval Maven at 9:00 AM on September 29, 2005

If it's just confirmation bias, then why did I never ever think to myself, "well, the nuts are sure calling tonight - must be a full moon" and find it wasn't? The only times I ever thought that, it turned out to be a full moon. Am I subconsciously aware of the moon's cycle?
posted by CunningLinguist at 9:27 AM on September 29, 2005

I don't know if it's true or not, but I don't see why not - the moon affects the tides and women's cycles - why couldn't it have an effect on craziness?
posted by agregoli at 9:54 AM on September 29, 2005

CunningLinguist - You've got to track the moon, not the "crazies".
posted by ObscureReferenceMan at 10:05 AM on September 29, 2005

CunningLinguist: The confirmation-bias explanation would be that you DID think that, saw that it wasn't a full moon, and have now forgotten about it because it didn't make any impact on you like it did the times you were right.
posted by solotoro at 10:44 AM on September 29, 2005

Am I subconsciously aware of the moon's cycle?

We're all aware of the moon's cycle. You may note devote conscious attention to it, but your body is aware of all manner of changes in light, direction of light, barometric pressure, etc.
posted by Miko at 10:51 AM on September 29, 2005

anyone who doesn't believe this needs to work night shift dealing with the public ... it is a real phenomenon

Again: the earth is flat because I can see it's flat.
posted by Miko at 10:51 AM on September 29, 2005 [1 favorite]

...I should add, I've examined this a lot, because I used to work the overnight shift on the city desk at a newspaper. So it's not that I haven't had experience with that type of night, and wondered at it. I have. But no one has produced real evidence.
posted by Miko at 10:52 AM on September 29, 2005

Right after high school I worked graveyard shift at the only 24 hour fast-food restaurant in a small hippy town. I saw more weird shit on each of the four full moons than I did for the rest of those four months combined.

I often thought that the people who did weird shit liked to worship the moon, or whatever, and that snowballed into a crazy night for everyone. I'd love to hear a cab driver's perspective.
posted by togdon at 10:59 AM on September 29, 2005

The next time things are crazy on the ward and there is no full moon, have your mom tell that to her co-workers. Ditto for the next time there is a full moon and things are quiet. Do you think these stories will get around?
posted by weapons-grade pandemonium at 11:10 AM on September 29, 2005

togdon: The cab drivers will likely tell you all the stories that coincide with the prevailing view. Many graveyard workers and cabbies must have boring full-moon nights, but those are not stories. Do you want to hear about the happily married Italian couple, Romero and Juliette, whose families approved of their relationship?
posted by weapons-grade pandemonium at 11:21 AM on September 29, 2005

I'm as skeptical as they come usually, but I'd like to hear from some nurses, cops, cabbies and night newspaper workers who DON'T have experience with higher numbers of loonies during a full moon. It seems to me it's those who don't actually have to deal with the public at night who are scoffing.
posted by CunningLinguist at 12:33 PM on September 29, 2005

I am the newspaper worker, and I don't believe in it. I have also been a teacher (it's also part of the lore in teaching) and I didn't find it to be true. I deal with the public in my present job. I am a total scoffer -- only the people who want to believe this believe it, so of course they talk about it quite a bit more. The rest of us have crazy days and quieter days as they come, without seeking an astrological reason.

Sure, in all these jobs I've had some times that were crazy that coincided with full moons; but I've had plenty of unaccountably crazy times, and plenty of full moons that were not unusually crazy.

An aggravating factor in the urban legend is that the definition of 'full moon' is generally very loosely interpreted. If you're having a crazy night, and someone says 'full moon', and you look it up, the moon might be + or - two to three days on either side and people will still attribute the effect to it. That means that in practice, six or seven days within each month are often interpreted as 'full moon'. I saw this happen a lot. If 20-25% of your month is 'full moon', then some crazy days are bound to fall in that window, creating the appearance that it's true.
posted by Miko at 2:50 PM on September 29, 2005

My wife does referrals for the local mental heath system. She and her co-workers definitely see an uptick in referrals on full moons. It may well be confirmation bias on their part, but it may also be the confirmation bias of those people who end up in the mental hospitals.
posted by holgate at 3:11 PM on September 29, 2005

I'm as skeptical as they come usually, but I'd like to hear from some nurses, cops, cabbies and night newspaper workers who DON'T have experience with higher numbers of loonies during a full moon. It seems to me it's those who don't actually have to deal with the public at night who are scoffing.

CunningLiguist -- after thinking about it, I realized that there's another reason you hear dissenting views so rarely. This belief is part of occupational folklore, sets of beliefs and customs that are associated with job descriptions. Occupational folklore has its purposes, which is why people like nurses and cops cling to it despite evidence. They pass it along to rookies, and it becomes part of the professional culture.

Even when the folklore itself is inaccurate, it often serves a utilitarian purpose which is desired. One purpose it serves is to strengthen the bonds between employees and build personal identification with the group: thus, scoffers aren't rewarded with group support, but believers are strongly reinforced.

Another purpose of occupational folklore is to normalize working conditions. Nurses and cops sometimes have to work in crazy conditions, where there are chaotic scenes going on all around them. To put this in the context of 'it's just what happens when there's a full moon...' helps to normalize this condition and build the expectation that these scenes will recur in the working environment, so you'd better be ready.

A third purpose, particularly in professions which involve danger or injury potential, is to give the worker a sense of control over events which are really quite unpredictable. By assigning a perceived pattern to weird behavior, workers create the illusion that they somehow understand the phenomena occurring around them, which increases their sense of mastery and control over the situation. Of course, it's an illusion.

Because the folklore supports the workers psychologically in ways that have nothing to do with its being true, these beliefs are extremely persistent. So that is a partial explanation of why you see few dissenters when questions like this.

Occupational folklore flourishes in settings of quick action, life and death, and heavy equipment. Many folklorists have worked on the lore of soldiers, tunnel workers, etc. I've witnessed similar phenomena with commercial fishermen, who have an incredibly complex array of superstitions such as this. When a vessel goes down, they'll point out all the 'reasons', such as that it left port on Friday, had something blue aboard, or had an upside-down hatch cover while loading ice. When vessels return safely despite having one of these jinxes, they were 'lucky' and 'got off easy', sometimes (supposedly)because of a counterjink or lucky piece or person aboard. If that's not the case, then the bad luck is still out there waiting to drop on you. So these aren't typically arguments you can win by using logic against entrenched beliefs.

But you can try. I at least like to point out that the perpetuation of the belief is more interesting than whatever the belief is.
posted by Miko at 3:17 PM on September 29, 2005

Again, holgate, is it that on the day of the full moon, there are more admissions on average than on the other 29 days? Or is it a loosely defined term of time -- say the two days before and after the full moon -- that gets to be credited to the 'full moon' effect? If there's paperwork associated with this, which I'd assume, couldn't it be shown in simple numbers? Or is it just an impression? Can you give, say, a year's worth of examples?
posted by Miko at 3:20 PM on September 29, 2005

So, I queried google to get the number of hits it thinks there might be for each day "January 20, 2001" through "December 25, 2004". Made a nice little chart. There is quite obviously no significant correlation at all with moon phase. Looks satisfyingly random. Very nice.

Then I repeated the search for the same dates plus the word "crazy". I dunno if I did something wrong, or what the hell is going on... but as far as I can tell right now, there appears to be a strong connection between web pages with the date and the word "crazy" on them, and the phase of the moon. It's a nice smooth curve, with the lowest numbers around the full moon, highest around new moon. Plus, a bit of a discontinuity right at the full moon, sort of.

If I hadn't already run the very same procedure without the "crazy", I'd be fairly sure I screwed it up somehow. But I can't think of any way I could get it wrong that would result in a smooth-looking curve like that. So, if anyone wants to try and find out what's up, I'd be happy to send you the raw data and source code.

Here are the number of hits (thousands) with "crazy" for each day in the lunar cycle up to 28, where 0 is the full moon:

0, 2283
1, 2280
2, 2368
3, 2244
4, 2352
5, 2286
6, 2300
7, 2334
8, 2391
9, 2715
10, 2540
11, 2552
12, 2662
13, 2727
14, 2757
15, 2747
16, 2732
17, 2737
18, 2685
19, 2702
20, 2725
21, 2672
22, 2596
23, 2675
24, 2668
25, 2585
26, 2635
27, 2595
28, 2575
posted by sfenders at 9:19 PM on September 29, 2005

Hmm. Well, okay, adjusting for the long-term trend towards more pages counted by Google containing the word "crazy", which screwed up my stats via interaction with google's monthly indexing cycle, and that pattern goes away. But another, more subtle one takes its place. Damn. There's an anomaly on the 23rd day of the lunar cycle. I'll take that as a signal that the illuminati have secretly planted this data in google for the sole purpose of driving me to madness. Good thing I didn't attempt this when the moon was full.
posted by sfenders at 10:11 PM on September 29, 2005

Ah, there we go. I got it to look almost random now. Much more realistic. My monthly adjustment was a bit wrong, and the first year or two of data was crap.

The day of and the day after the full moon still just happen to be the lowest count of the lunar cycle though. Sort of suspicious-looking, but probably just noise. Whew.

30233
30175
32079
30963
32453
31727
32104
31763
31515
31547
32690
31395
32259
32825
30956
31415
31808
31772
31179
32101
32061
31079
32218
34060
33127
31640
32434
32333
31726
posted by sfenders at 10:38 PM on September 29, 2005

I get the confirmation bias idea but those of you arguing that point are yourselves working on a bias that the studies done to date have disproved the observations of all these people. Look at the studies. They all study extremely final things: traffic accidents, suicides, homicides, burgleries, etc..

The observations people are giving aren't that on full moons more people are showing up dead or calling about burglaries. Their saying people are just acting weird. Off. Slightly strange. We've all had those days and don't run off and kill someone because of it, we just get pissy and try to make it through the day to get to sleep and hope the next day is better.

I don't think your going to see the effect in any sort of agregate of information like "number of vehicle accidents per night" nor even "number of jerks cutting other cars off per night". The effect is subtle, just enough to fray nerves and make people think things are just a little weird that day. You'll get folks repeatedly driving fast and then slow and then fast again. People making lane changes for no reason, or driving too close to the sides of the road. Police might notice more people talking to them in a more disjointed manner. It'd be harder for them to do their jobs as such, and thus make for the more stressful day their complaining about.

Can anyone show me the study that disproves that? How can it even be quanitatively measured? It's more of a qualitative problem.

And can we please go easy on the confirmation bias bandwagon? Jeez. We wonder why non scientific folks are afraid of science... I would be too if I had everyone telling me my observations are pure tripe.
posted by jwells at 11:32 AM on September 30, 2005

I'll see your Straight Dope column and raise you two more!

1. There is no link between the lunar cycle and the menstrual cycle. (In re:)

2. Cohabitating women don't menstruate at the same time.
posted by Ian A.T. at 11:52 PM on September 30, 2005