How tall was Princess Jasmine’s mother?

For who could ever learn to love… metrology. Photo by Jennifer Lynn (www.flickr.com/people/129451096@No8)

 

We can learn a lot of important lessons about genetics from Disney. For example, from The Muppet Christmas Carol (released in 1992 by Walt Disney Pictures) we learn that the being a frog genes are on Kermit’s Y chromosome. Thus when Kermit and Piggy have children, the boys are all frogs and the girls are all pigs. We also learn that Muppet frogs and pigs are close enough as species to interbreed, although we can’t comment how close without observing the fertility of their offspring. These are slightly more confusing lessons. I also assume that the reason that Muppet Tiny Tim couldn’t walk well, was that he was actually still a tadpole and just had pushy parents. After all there’s only one more sleep until metamorphosis.

The biological processes behind Beauty and the Beast are slightly more difficult to work out. Mrs Potts is a teapot and her son, Chip, is a cup. We know that the curse that transformed the servants of the castle into theatrical IKEA stock had been in place for 10 years. Chip seems younger than this. It should be hoped that from the moment they were transformed, the staff didn’t age and that young Chip was one of those who the witch literally made a mug of when she cast her spell. Otherwise we have to consider the idea that a teapot got pregnant and gave birth to a cup. A tale as old as time.

The biological variation within that happy crockery family is far from unique within the world of Beauty and the Beast. A person conducting a preliminary comparison of Belle and her father, Maurice, would be hard-pressed to find much of a family resemblance. Belle is tall and slim, while Maurice more closely resembles an owl that rolled itself in pastry and finished the disguise with a moustache it fashioned from leftover rodent hair. I’m not judging. I have a similar body type. The same could be said of Aladdin’s the Sultan and his daughter, Princess Jasmine. Again Jasmine is tall, with barely enough abdomen to contain her colourful Disney internal organs, while the Sultan is practically spherical and would struggle to see over a crouching slug while he was wearing platform shoes. For this to work, Jasmine and Belle’s mothers must have been 10 feet tall and essentially boneless. Either that, or Disney fathers are constructed entirely from recessive genes.

We don’t have to guess at the heights of Jasmine and Belle’s mothers. These can be calculated from the heights of the princesses and their fathers. Within medicine, a person’s adult height can be estimated from their parents’ heights, using an estimation called the mid-parental height. The calculation is as follows:

Mid-parental height = Mother’s height plus Father’s height (plus 13 for boys, -13 for girls) and divide by two.

NB: Heights are in centimetres (cm).

Filth!

This method isn’t perfect. For example, it doesn’t allow for extremes of parental height. Very short or very tall parents tend to have offspring of a less extreme height through simple regression to the mean. This wouldn’t be predicted by the mid-parental height estimation. However, it is a useful tool to help assess an individual child’s growth and to calculate the height of fictional princesses’ mothers. By rearranging the equation, we find that

Disney Mother Height = (Disney Daughter Height x2) plus 13, minus Disney Father Height

This idea can be tested in cases where we see both of the parents and the daughter e.g. Aurora in Sleeping Beauty and Rapunzel in Tangled.

Unfortunately, Disney doesn’t provide us with the vital statistics of the characters. Which is pretty thoughtless of them. As a result, we’re going to have to make some crude estimates. In Sleeping Beauty, Aurora’s father can be seen holding a wine bottle. Given that he ended up sleeping for 100 years, it must have been some pretty strong stuff. Or a witch did it. A standard wine bottle is approximately 30.5 cm and from a couple of stills from the film, Aurora’s father looks to be about 5.8 wine bottles tall. As a side note, if you start to measure you’re height in wine bottles, it might be time to take out the recycling. This may not be the least of your problems. We can therefore estimate Aurora’s father to be 176.9 cm (5 ft 10 inches) tall. From more stills, Aurora’s mother looks to be the equivalent of Aurora’s father’s head shorter than Aurora’s father. A human is roughly 7.5 heads tall so Aurora’s father’s head must be 23.6 cm, which makes Aurora’s Mum 153.3 cm (5 ft 1 inches) tall.

From the film, Aurora comes up to her father’s shoulders and so appears to be about 153 cm (5ft) tall; similar to her mother. Using the mid-parental height equation, Aurora’s height is estimated at 158.6 cm (5ft 2 inches). So we’re about 5 cm off. However, in Sleeping Beauty, Aurora is 16 years old. A woman’s final adult height can be reached at around 18 years of age, so perhaps it’s not impossible for her to grow those last 5 cm, especially if she manages to eat well and get plenty of sleep. This probably isn’t a problem.

We can test our height prediction in a similar fashion with Rapunzel from the film Tangled. In one scene, Rapunzel’s mother is observed holding a book. If we assume the book to be one octavo (a unit of measurement which should be familiar to Terry Pratchett fans, and is approximately 15.3 cm) and we can see that Rapunzel’s mother is about 10.5 books tall. We can guess Rapunzel’s mother is 160.7 cm (5ft 3 inches) tall and that her librarian is messy. Rapunzel’s father is roughly another book taller than Rapunzel’s mother, making his height 176.0 cm (5ft 10 inches).

From pictures, Rapunzel is about one third of her mother’s head shorter than her mother. If we estimate her mother’s head to be 21.4 cm long, this gives Rapunzel’s height as 153.6 cm (5ft). The mid-parental height calculation predicts Rapunzel’s height as 161.9 cm, so we’re about 7 cm off. As with Aurora, Rapunzel may still grow a bit more (although she’s 18 years old in the film) and we might argue that she is shorter due to being mistreated and held captive in a tower. Perhaps the weight of all that hair is compressing her spinal column and making her shorter. Overall, our height estimates using mid-parental height are within 10% of what we see on screen, so should be adequate for estimating the heights of Jasmine and Belle’s mothers.

Quite a bitey tape measure. Photo by Tony Hisgett (www.commons.wikimedia.org/w/index.php?curid=27317596)

In Aladdin, at some stage, both Jasmine and the Sultan are shown next to their pet tiger. A male tiger can be 110 cm from the ground to the shoulder. Judging by where the tiger comes up to on Jasmine, we can estimate her to be 170 cm (5 ft 7 inches) tall. Similarly, we can estimate the Sultan to be 130 cm (4 ft 3 inches) tall. The tiger method for measuring height is an exciting one, but probably won’t catch on with parents. It’s difficult to see the pen where you’ve marked-off your child’s height on the side of a tiger. Also, it’s a tiger. Using the Disney Mother Height Calculator, Princess Jasmine’s Mum’s height is estimated to be 223 cm (7ft 4 inches).

 

To put this height into context, the World’s tallest living woman, Siddiqa Parveen is estimated to be 7ft 8 inches tall (2.1 tigers, 15.3 books or 7.7 bottles of wine). Although of course she isn’t animated. Or fictional. And we cannot work out Siddiqa Parveen’s mother’s height using the Disney Mother Height calculator. That would be a ridiculous waste of time. There are other reasons.

Now it’s Belle’s turn. Luckily, in Beauty and the Beast, both Belle and her father get attacked by wolves. Luckily for us anyway. Like most wolf attacks, it’s shown as a bad thing in the story. An adult wolf is approximately 83 cm from ground to shoulder. In terms of height, Belle looks to be a double wolfer, coming in at 166 cm (5 ft 5 inches) tall. Belle’s father, Maurice, is approximately 1.67 wolves tall and therefore has a height of about 138.6 cm (4 ft 7 inches). Using the Disney Mother Height Calculator, Belle’s Mum’s height is estimated to be 206.4 cm (6ft 9 inches).

Of course, all of this assumes that Maurice was Belle’s biological father and that the Sultan was Jasmine’s. It’s likely that they were. Belle had a whole library at her disposal, so you’d think she’d have the necessary information to hand to work out if her father wasn’t related to her. Although she may have been to busy buying new furniture. All of hers recently turned into people after all.

 

How bad is Stormtrooper aim exactly?

A Stormtrooper gun. It’s possible they don’t know what these are for. Photo by Roy Kabanlit.

For some unknown reason, I’ve been thinking a lot about Star Wars recently. Going forward, I’ll assume you’ll be familiar with the events and characters of at least the first six films. If not, what have you been doing? Living in a recent, recent time in a galaxy that’s very close to here? Broadly speaking, this post inevitably contains minor spoilers for Episodes II−VI of the Star Wars films. If you haven’t seen them, inexplicably want to find out about Stormtrooper aim and don’t mind knowing some plot details, then feel free to read on.

There are some characteristics of characters or groups of characters within the Star Wars register that are widely held to be fact. This may be despite them not being explicitly stated within the films. Red lightsabers are for the evil, Jar Jar Binks is rubbish and Stormtroopers have worse aim than a urinating drunk man in a vibrating chair trying to hit a toilet located on The A-Team van.

Can Stormtroopers really be that bad at shooting? There is an assumption that the Empire want effective troops to maintain their evil hold of the galaxy. Surely they get some training in marksmanship rather than signing up, being given armour that doesn’t even protect against Ewoks (weirdly, the autocorrect on my phone turns ‘Ewoks’ to ‘useless’) and told to, “go forth and do bad stuff.” In fact, Obi Wan Kenobi in Episode IV: A New Hope comments, “only Imperial Stormtroopers are this precise” when examining some blast marks on a massive used droid dealership tank. So Stormtroopers have a reputation in the Star Wars galaxy for good aim. There are a number of explanations for this:

• Stormtroopers have good aim compared to everyone else, who is really awful (maybe the Star Wars galaxy is windy, wobbly or makes everyone slightly drunk for reasons)
• Stormtroopers do have rubbish aim, but are good at marketing (history may contain examples where propaganda has been used by states with less than altruistic intentions)
• Stormtroopers do have rubbish aim, but everyone is concerned about their self-esteem and tells them otherwise
• Stormtroopers normally have good aim, but during the events of the Star Wars films develop bad aim; almost as if the Imperial Stormtrooper Marksmanship Academy has informed its troops that they should imagine themselves as antagonists in a series of films that won’t progress very far if the protagonists keep getting shot

Seems about right. Photo by The Conmunity – Pop Culture Geek from Los Angeles, CA, USA.

Why would Stormtroopers’ aim be so bad? Is it their tools? This seems unlikely given that non-Stormtroopers steal Stormtrooper weapons and seem to have no issue with shot accuracy or a gaining a reputation for terrible aim. Perhaps their helmets obscure their vision and make aiming difficult. Possibly, but the Stormtrooper helmet eye holes don’t appear to be any smaller than human spectacles, which can’t be said to obscure vision. Not if they’re doing their job. They are tinted though, which may make aiming difficult when in badly lit conditions and make Stormtroopers look like posers when wearing their helmets indoors.

Perhaps Stormtroopers are just human. In spite of the impression given to us by world events, it is actually quite difficult to get one person to actively shoot to kill another person. During World War I, British Lieutenant George Roupell reported that the only way he could get his soldiers to stop firing above their enemies’ heads was to beat them with his sword while ordering them to aim lower. Later reports of Lieutenant Roupell winning a medal for being a slightly charming human being may have been an exaggeration. Similarly in World War II, US Brigadier and army analyst S.L.A. Marshall reported that during battle, only 15−20% of soldiers would actually fire their weapons. This should perhaps be considered sceptically, as later analysis hints that Marshall may have fabricated at least some of his results. A 1986 study by the British Defense Operational Analysis Establishment’s field studies division found that in over 100 19th- and 20th-century battles, the rate of killing was actually much lower than potentially should have been the case given the weapons involved. Some reports from the Vietnam War state that the average US solder fired approximately 50,000 rounds before they hit their target.

Lieutenant Colonel Dave Grossman claims that psychologically this is a result of soldiers choosing to posture (falsely display active combat to attempt to intimidate or deter the enemy) rather than fight, flee or submit to the enemy. In this regard, posturing is chosen as the least costly (psychologically, socially and physically) of the four possible options available to a soldier in combat. In terms of Star Wars, we know that the Empire is not adverse to a bit of posturing with their giant shooty snow dinosaurs, Nazi-chic uniforms and ‘tis no moon space stations. Perhaps the legendary terrible aim of the Stormtroopers is simply due to a human tendency to try and look scary rather than murder another individual. Should they be renamed as ScaryLookingHugtroopers?

To even start to get an answer to this we need to at least get some idea of the accuracy of Stormtrooper aim. Luckily, counting exists and can be used get numbers for percentage purposes. In order to calculate the Stormtrooper hit rate, the number of shots fired by Stormtroopers in Star Wars Episodes II-VI (the ones with Stormtroopers and that aren’t currently in cinemas) was counted. The number of times that the Stormtroopers hit what they were aiming at was also counted.

Let the Wookie in. Photo by William Tung from USA (SWCA – A Stormtrooper and Chewie) [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)%5D, via Wikimedia Commons

Stormtroopers were identified as such by their armour. Han Solo and Luke Skywalker were not counted as Stormtroopers when they were wearing said armour as a disguise. The Stormtroopers wearing the special armour in Episode V: The Empire Strikes Back (the ones dress as Arctic pepper pots) and in Episode VI: Return of the Jedi (the ones with helmets like sad bulldogs) were counted as Stormtroopers. A hit was counted as such when a Stormtrooper launched or fired a projectile that hit what the Stormtrooper was judged to be aiming at. A miss was defined as when that stuff happened but the projectile didn’t hit the target. When the final resting place of a projectile was not seen on screen, it was presumed to be a miss, unless there was some kind of sound effect that hinted otherwise (like a character saying, “Ouch, this laser wound is relatively painful”). Only shots fired from hand weapons were counted. Shots fired from vehicles were not counted as some sort of computer-aided guidance may have been used. We know they have that and that’s it’s not as good as trusting your feelings when you’re a bit forcey.

It should be noted that the resulting Stormtrooper accuracy ratings will be rough estimates only. It’s quite difficult to count shots fired in the reasonably frenetic action scenes of these films and it is likely that the number of shots fired here is an underestimate. Also it’s not real and this may be a waste of time.

Table 1 illustrates the accuracy of Stormtrooper aim for each of the films and the overall Stormtrooper shot accuracy rate across all of the films. Stormtrooper aim appears to be most accurate (37.4%) in Episode III and least accurate in Episode IV. Otherwise Stormtrooper accuracy is reasonably consistent at around 7% across the other episodes with an overall accuracy of 9.8% calculated across all of the films. Of note is that Episode III is the only film where Stormtroopers can feasibly be argued to be on the side of good. It would seem that it’s being evil that’s bad for your shooting accuracy.

Table 1: Stormtrooper shot accuracy in the Star Wars films.

However, many have noted that during the events on the Death Star in Star Wars Episode IV: A New Hope, the plan was to let Princess Leia and company escape so that the Empire could locate the Rebels’ headquarters and blow it up along with the planet they were on. The Empire is apparently not that concerned about conservation. Or about killing lots of people. As such, it is likely that the Stormtroopers firing on the protagonists had been ordered not to kill their escaping prisoners. This may change the accuracy rate for this film as we suddenly have to count every miss in these sequences as a hit. So the space abacus (calculator) was broken out again and the Stormtrooper shot accuracy rate for Episode IV and the overall Stormtrooper shot accuracy was recalculated. Table 2 shows these new figures.

Table 2: Stormtrooper shot accuracy in the Star Wars films (assuming they were aiming to miss during those bits on the Death Star in Episode IV).

Suddenly, the accuracy of Stormtroopers doesn’t look so bad. In order to determine if this is the case, it is necessary to compare these rates with others. Ideally, this would be with other accuracy rates from the Star Wars films (probably not Greedo’s) in order to remove any confounding windy, wobbly drunken influences that the Star Wars galaxy might have. I didn’t do this for reasons of time, illness, difficulty and laziness. However, we do have some shot accuracy rates from our galaxy. These are shown in Figure 1.

Figure 1. Comparison of Stormtrooper shot accuracy with real-world examples.

We can see here that Stormtroopers don’t fair too terribly, with greater shot accuracy than archerfish and the average US soldier (aiming at a human-sized target) at 300 metres, but lower shot accuracy than a US sniper at 600 metres. So Stormtrooper aim suddenly doesn’t seem so bad. In terms of accuracy. Their aim is obviously “bad”. They tried to shoot Chewbacca!

If we discount the US sniper (unfair to compare to a trained specialist with more time and calibrated equipment) and the archerfish (a fish which spits water at land-insects in order to eat them and which is rarely found in conditions of modern warfare) the Stormtrooper is four-times more accurate than our only remaining comparator, the average US soldier aiming at a human-sized target from 300 metres. If we accept that reduced soldier accuracy is due to posturing in favour of other combat choices, it suddenly seems that Stormtroopers are choosing to fight rather than flee, posture or submit. This makes Stormtroopers seem less human and more terrifying. Fitting soldiers for the Dark Side indeed and certainly not deserving of their reputation for inaccuracy! Unless they didn’t read the Death Star memo. Then, they’re just average.

 

 

What If Disney Princesses Were Placed Into Vaguely Relevant Graphs?

Does Sean Bean Always Die at the End?

The Alpha Sean Bean, shown here to be still alive.
“Sean Bean TIFF 2015” by NASA/Bill Ingalls. Licensed under Public Domain via Wikimedia Commons .

There’s a quote from a character in The Lord of the Rings: Fellowship of the Ring, and J.R.R. Tolkein’s character from some book or other, that has been doing the rounds as an internet meme for quite some time: “War makes corpses of us all.”  Of course you all know it, it’s ridiculously famous, after all, one does not simply forget a Faramir quote. Much better than Boromir. In Sean Bean’s case however, the quote might as well be “appearing in a role in television or film makes a corpse of me, Sean Bean.” Sean Bean is well known for dying in films. So much so, that there exists a campaign specifically against the further onscreen killing of Sean Bean. At least, I think it still exists. It might have died.

Basically it is a fairly common assumption that if Sean Bean is in something, he will most likely not make it to the end. However, everyone knows what happens when you assume; you make a prick of yourself. Is it actually true that Sean Bean always dies? In psychology, confirmation bias describes the tendency for people to better recall information that confirms their existing beliefs than information that would refute them. The frequency illusion is where something (it can be an event or just an object) which has recently been brought to a person’s attention suddenly seems to occur or appear with greater frequency than it did before it had been noticed. This is also known as the Baader-Meinhof Phenomenon and once you know about it, you’ll start seeing it everywhere. So it is possible that the appearance of Sean Bean’s repeated celluloid mortality is a function of some common cognitive biases rather than him actually ending more times than a Sunday furniture sale. The following information that was collected to test this may contain spoilers for Sean Bean projects. Unless you believe the appearance of Sean Bean in a cast list is in itself a spoiler.

Using some sort of internet search engine (if you want to find a similar one, you can look it up on Google) all of Sean Bean’s roles in film and television were listed to create a population of Sean Beans. From here forward, the collective noun for Sean Beans used will be “population” rather than the perhaps more common “can” or “cemetery.” Sean Bean’s roles in theatre or performing voiceover in video games were not included due to a combination of being too difficult to include, laziness and the words “Sean Bean” starting to lose all meaning. The actual actor Sean Bean (the Alpha Sean) was also included, as while technically it is an ongoing role, we do know with reasonable certainly that Sean Bean will die at the end of it. The Alpha Sean was not included in any cause of death calculations in case I end up as a suspect in a future murder investigation. Jupiter Ascending was not included for obvious reasons.

The number of times Sean Bean was dead at the end of a film/TV show and the number of times Sean Bean was alive at the end of a film/TV show were counted and used to calculate the incidence of death for the total population of Sean Beans. The incidence rate is the number of new cases of a disorder or death within a population over a specified period of time. This is commonly express in terms of per 100,000 persons per year. In terms of deaths, this in some ways can be seen as equivalent to the Mortality Rate. Some basic demographics, causes of deaths and intentionality of deaths were also calculated.

The demographics for the population of Sean Beans are shown in Table 1.

Table 1. Sean Bean Demographics

Characteristic	Sean Bean Numbers
N	75
Mean (SD) age, years	6,0810,851.05 (523,114,369.60)
Species, n (%)
Actor	1 (1.33)
Human	71 (94.67)
Lion	1 (1.33)
Portrait	1 (1.33)
God	1 (1.33)
Survival
Alive, n (%)	45 (60.00)
Dead, n (%)	30 (40.00)

The incidence of Sean Bean deaths across the total existence so far of Sean Beans (6000 BCE to 2072) is 4.85 per 100,000 person per year. The causes of Sean Bean death and intentionality of Sean Bean death are shown in figures 1 and 2, respectively. The most common cause of death was being shot by a gun. The best cause of death was fall from cliff due to a herd of cows. Most Sean Bean deaths were intentional (as a result of homicide) compared with accidental and orcicide.

Figure 1. Cause of Sean Bean death.

Figure 2. Intentionality of Sean Bean death.

The aim of all this Beanian death numbering was to determine if there was any truth to the common belief that Sean Bean always dies at the end. Examination of a fairly complete population of Sean Beans shows that this is not the case, with 60% of Sean Beans managing to survive the time it takes for many film and TV directors to tell a story. If you are a Sean Bean though, it seems you are most likely to die by being shot by a human. There may be some money to be made in a line of Sean Bean-specific bullet-proof vests.

So why is the belief that Sean Bean always shuffles off the mortal coil at the end so common? The application of confirmation bias to this has already been discussed, but for that particular bias to take effect, there must be an existing belief to confirm. The earliest manifestation of Sean Bean’s tendency for premature televisual corpse shenanigans that I could be found was approximately around his fourth appearance. However, at a preliminary glance, Sean Beans don’t seem to kick the bucket particularly often early on in the ascendance of Sean Beans to make any reputational impact.

If we divide the appearance of Sean Beans into tertiles (an ordered distribution divided into three parts, each containing a third of the population, not an aquatic reptile with a shell) and look at the proportion of deaths as time progresses, we get something that looks like figure 3.

Figure 3. Proportion of Sean Bean deaths by Sean Bean time tertile.

We can see that if 3 is the most recent tertile and 1 is the furthest in the past, then the Sean Bean death rate appears to be greatest in the middle of the population’s progression through time. In psychology, the serial position effect describes the tendency for people to recall items earlier (the primacy effect) and later (the recency effect) in a list the best, with items in the middle being recalled the least. This would not explain the Sean Bean always dies reputation, as in such a model we would expect more deaths in the first and last tertile. Besides, one explanation for the serial position effect is that earlier items are stored more effectively in long term memory than the other items, while more recent items are still present in working memory and are thus easily available for recall. This would only apply to these data if people experienced Sean Bean necrosis as a list in front of them, which most people (besides me) don’t. Even if the data matched a serial positioning explanation, it would be a stretch (i.e. wrong) to use it to explain the Sean Bean deceased at the finale reputation phenomenon.

Rise of the Nicole Kidmen would be a good episode of Doctor Who.

Characters don’t become instantly well known in popular culture. It takes time for a reputation to build and saturate society. In this respect, perhaps we can consider the middle tertile to be more akin to the starting point for a reputation i.e. Sean Beans will be more well known, with more opinions being formed about them. The Sean Bean death rate here is 52%, meaning that during this period Sean Beans were slightly more likely than not to die at the end. This may be enough to start the rumour of Sean Beans’ non-existence by the credits and establish a source for confirmation bias.

Characters don’t exist in isolation. They usually exist in a complex ecosystem of other populations. The Sean Bean population exists alongside the population of Bruce Willises (Willi?) and the population of Nicole Kidmans (Kidmen?) among others. Important data to consider would therefore be how often Sean Beans die in comparison to other populations. If the comparative death rate of Sean Beans is noticeably higher than that of other comparable populations, then this may explain the Sean Bean clog-popping conundrum. Future “research” should focus on this (I can’t be bothered right now).

It was suggested to me by KTBUG (kgwright73) that the popularity of the mode of presentation of Sean Bean would have an impact on the perception of his tendency for pushing up the daisies. It seems feasible Sean Beans die in more popular things and live in less popular things then the public perception would be that of a gentleman prone to leaving his life behind. To this end (where available) I took an average of lifetime box office takings for films where Sean Bean died and films where Sean Bean lived (figure 4).

Figure 4. Average lifetime box office takings by Sean Bean survival.

Figure 4 shows that films where Sean Bean shook hands with the Grim Reaper on average took more at the box office than films where Sean Bean continued respiring. If we use this as a crude measure of popularity (and it is very crude, subject to bias from missing TV shows and films where I simply couldn’t get the info) and impact on cultural awareness, then films where Sean Bean becomes an ex Sean Bean seem to have made a larger cultural impact. This could certainly be at least one source of the idea that Sean Bean always dies.

Please note, I am in no way suggesting that Sean Bean dying in it makes a film popular. As the old saying goes, “Sean Bean’s death correlation, does not prove film popularity causation.” You all know it.

In conclusion it would seem that Sean Bean’s reputation for always dying at the end is somewhat over exaggerated, with a death rate of approximately 40%. Sean Beans are most likely to die from being shot intentionally by a human or from being in the middle of their career trajectory. The Sean Bean Ex-Parrot Meme may be best explained by a high death rate at a time when Sean Beans were likely to be reaching their maximum prevalence in the public eye and by films which feature a Sean Bean death having made a larger cultural impact than films that feature a living Sean Bean at the end. These perceptions feed into confirmation bias. And then Sean Bean died.

The Guardian of the Galaxy

A Bad Case of the Zombies: Could a virus really cause World War Z?

A zombie playing the sousaphone. I wanted one playing the trombone because of the tenuous trombone/bone/zombie connection. Ho hum.

The other day I went to see the film, World War Z. It was fine and thus ends my review of my enjoyment of it. Anyway, the real World War Z will of course be between those who pronounce it “zed” and those who pronounce it “zee”. World War Z is based on the 2006 novel by Max Brooks (a follow-up to his 2003 book, The Zombie Survival Guide). Both books are excellent and if you’re not too bored of zombie-based fiction then you should read them. I say this because there seems to have been a recent upsurge on things about zombies of some kind. The zombies are everywhere, which I suppose is ironic. The film stars Bradley Pitt as a retired United Nations employee who must travel the world to find a way to stop a zombie-like pandemic.

In the film being a zombie (Zombieism? Esprit de corpse? Zombosis?) appears to be caused by a viral infection, primarily caught by being bitten by a zombie. Those who are bitten appear to die within about 30 seconds and then reanimate with slightly cloudy eyes. They then become very aggressive and begin to chase down victims to bite them and spread the infection. They do not appear to eat their victims; rather keep on going just generally being runny and a bit bitey. I say runny as in they run a lot rather than hinting at any advanced state of decomposition. Although eventually the zombies do appear to go a bit rotten.

I accept that all this doesn’t have to be dead-on realistic (ahem) but there are a few problems with the concept. It’s assumed that the mass zombification is caused by a viral pandemic. Yet time from being bitten to turning into a zombie appears to be too rapid for this to be the case. It would take a bit longer for whatever virus it is to circulate, invade cells, hijack their genetic machinery and start producing copies of the virus and manifest symptoms. Especially given that the virus appears to completely take over the host’s central nervous system and musculature while leaving the rest of them deceased. Like a more infectious version of Britain’s Got Talent.

While viruses certainly can be deadly they generally need the thing they’re in to be alive to make more virus and spread them. This might be by sneezing in their co-worker’s face, not washing their hands, licking fruit bowls etc. The zombie virus doesn’t appear to need this. It kills the host and still somehow has them running around. Where is the host’s energy coming from? Could the humans all just hide and wait for the zombies to fall apart? Granted this would make the film quite dull. Nobody wants to watch a film where people eat sandwiches in a bunker waiting for their enemy to decompose. Although Panic Room is OK.

The idea however that an infection can control its host’s behaviour to help its spread is well established in nature. For example, malaria is an infectious disease spread by mosquitoes, caused by one of five species of the Apicomplexan parasite, Plasmodium. Most deaths from malaria are caused by Plasmodium falciparum. It really is an awful disease with the WHO estimating that in 2010 there were 219 million cases of malaria resulting in 660,000 deaths. As I’ve hinted, Plasmodium can change the behaviour of mosquitoes to spread itself faster and wider.

The common Plasmodium Puppet. Also known as the mosquito.

Once in a mosquito, Plasmodium needs time to move to the mosquito’s gut to mate and reproduce to form ookinetes. These are a sort of mobile egg. The story of Plasmodium really ruins Humpty Dumpty. Ookinetes develop into sporozoites (Literally: “animal seed”. Don’t go planting your hamsters though!) and travel to the mosquito’s salivary gland. Prior to this it doesn’t do the Plasmodium much good for the mosquito to bite someone with the risk the mosquito might get killed during the attempt. So Plasmodium tries to alter the mosquito’s behaviour to prevent this. For a mosquito to get your blood it has to drive its proboscis through your skin and find a blood vessel. The longer this takes the greater its chances of being noticed and squashed. Like if McDonalds killed you if you queued too long rather than years later of heart disease. If a mosquito finds it too difficult to draw blood they’ll quickly give up.  A mosquito with ookinetes in it will abandon biting quicker than an uninfected one.

However once the sporozoites reach the mosquito’s mouth, it benefits Plasmodium for the mosquito to bite as much as possible.  The Plasmodium at this stage appears to make the mosquito “hungrier”, causing it to drink more blood and visit more hosts to get it. In these ways and more Plasmodium is manipulating its hosts behaviour to reproduce itself and spread more easily.

Some species of tapeworm live in the three-spined stickleback but also spend part of their lifecycle in the birds that eat these fish. The tapeworms can alter the behaviour of the fish making it more likely they’re caught and eaten. As you’d expect, sticklebacks try to keep away from heron. They stay away from the surface and if a heron appears they dart away. Sticklebacks infected with tapeworm appear to become more fearless, staying near the surface to feed even if a heron is about. These are more likely to be eaten and the tapeworm gets where it wants to go; into the heron.

Similarly, Toxoplasma gondii, a protozoan of “don’t go near the litter tray if you’re pregnant” fame, needs to move between rats and cats and back again to complete its lifecycle.  A healthy, uninfected rat will normally become anxious when it smells cat urine staying away from where they smelled it.  They will literally piss off. Rats infected with Toxoplasma however do not become anxious when they catch the scent of a cat, do not avoid it and increase their chances of becoming dinner.

Toxoplasma also appears to alter the psychology of humans it infects. Men infected with Toxoplasma become less willing to follow rules and less worried about being punished for breaking these rules. Women infected with Toxoplasma become more outgoing. Toxoplasma: the party protozoa! I probably shouldn’t get into marketing. It is not fully known how this occurs although there is some evidence that Toxoplasma increases production of the neurotransmitter dopamine and in males, increases testosterone levels.  It should be noted that this evidence is largely from rats. A lot of evidence is.

Afraid? Are you a man or a mouse? Or are you infected with Toxoplasma?

All of our examples have been parasites, but the infection is World War Z is cited as a virus, which I guess technically can be seen as a parasite. Can a virus alter its host’s behaviour to aid its spread? You bet your hot butter on toast it can! The baculovirus, infects the caterpillars of the European gypsy moth and causes them to climb to the tree-tops. Once there they die and liquefy, releasing thousands of viral particles to rain down and infect more unfortunate caterpillars. In this way Lymantria dispar forces the caterpillar to turn itself into a piñata and explode itself, raining down sweets i.e. a nasty virus, on other unsuspecting future piñata-pillars.

Rabies is another viral disease that manipulates its hosts’ behaviour. Rabies causes acute encephalitis in warm-blooded animals, including humans. More than 55,000 people, mostly in Africa and Asia, die from rabies every year. There are three stages of rabies progression. The first is characterised by behavioural changes and is known as the prodromal stage. The second is the excitative stage. This stage is also known as “furious rabies” as the infected animal is exceptionally aggressive, hyper-reactive and will bite with little provocation. The virus is present in the nerves and saliva and as such the route of infection is usually, but not always, by a bite. With the encephalitis induced aggression and biting, the virus’ manipulation to aid its spread becomes clear. The third stage is the paralytic stage (due to motor neuron damage) which is followed by death.

The excitative stage of rabies is the example we’ve seen that is most similar to our zombie virus and in fact in the film the zombie pandemic (a good name for a band) is initially mistaken for an outbreak of rabies. So could a virus cause the changes seen in World War Z and cause a zombie pandemic with Brad Pitt staring concerned across various international scenes? Probably not, but parasites and viruses can certainly manipulate their hosts behaviour in a variety of subtle and not-so-subtle ways. Although ultimately it might be preferable to have your emotions and behaviour manipulated by watching a film. Panic Room is OK.