A joke worth mentioning

My friend Matt is always up for a good joke, worth repeating. I love the guy. The other day, he told me this one, which I will paraphrase.

So there is this student and a teacher. The teacher asks the student, "So imagine there are three birds on a telephone wire. I take out a gun and shoot one of them. How many birds are left?"

The student answers, "None. The sound of the gun frightened away the two other birds"

The teacher says, "I like how you think, but you're wrong. There are 2 birds left. I appreciate how you think, though!"

The student ponders this.

After a while student says to the teacher, "So there are three women on a bench. One is eating a triple ice cream split, the other two are eating a low fat frozen ice cream. Which one is married?"

The teacher thinks for a minute. "Well probably the one that is eating the ice cream split."

The student replies, "No, the one that's married is the one that's wearing the wedding ring. But I like how you think."

There has to be some kind of truth to this one, don't you think?

Water water everywhere, but not one drop to drink

After class, I go around the room where I teach and pick up and discard bottles and cans. One thing I've noticed recently is that people often leave plastic bottles of water laying around the room, half full. This has always bothered me, because the night watchman, an older gentleman, has to then go around and pick up the bottles. But this has gotten me thinking.

At my university, a 12 fluid ounce bottle of water costs $1.50. A gallon has 160 ounces in it, so there are roughly thirteen 12 fluid ounce bottles of water in the gallon. That means that people are paying $19.50 per gallon of water by buying that bottle of water, which they leave on the ground.

People complain that gasoline costs will hit $4 a gallon this summer. However, they have no problem leaving half a bottle of spring water that costs $19.50 a gallon on the floor of my classroom. Of course, you're not really paying 19.50 for the water - you get the plastic bottle, itself made of petroleum.

When I brought this up this evening to the night watchman, she shook his head. "I guess these kids have some rich parents paying their way through..."

Why we should all eat more chicken

Former playboy model Jenny McCarthy has written a piece appearing on CNN's website regarding her suspicions that the chemicals in vaccines are implicated in the development of autism. You see, McCarthy has a child who was diagnosed with autism some years ago. McCarthy has since become a proponent of a movement in the autism community claiming that the etiological origin of autism can be traced to vaccines given during the second year of life.

In her piece, McCarthy states that a recent federal court "conceded" that vaccines "may be" implicated in the development of autism. If only the federal court is made up of scientists rather than lawyers!

Apparently, there is a considerable number of parents who have joined McCarthy, armed with little scientific data, making wild and speculative claims of conspiracy between the government, doctors, and the pharmaceutical industry in hiding the risks of vaccination. At first, their fingers pointed towards the mercury compound thiomersal that was used as a anti-bactericide in vaccines. When panel after panel of scientific organizations determined that there was absolutely no evidence of thiomersal's relation to autism arose, the vaccinations themselves were blamed.

I'm not buying the argument. Most scientists claim that the link between vaccines and autism is a myth, and I believe them over the former playmate of the year. As cognizant organisms, we tend to seek out connections between events. It so happens that vaccines are given around 15 months of age, and it is around this time that the symptoms of autism begin to emerge. It is easy to point one's finger at vaccines and claim that they cause autism because the mechanisms underlying how vaccines work and how autism develop are poorly understood, either by the general public or most scientists. Many children are safely vaccinated and do not develop autism. Children who do not get vaccinated out of autism fears are threatened by far more life-threatening illnesses such as influenza or tetanus.

In part, the reason people may believe in a link between autism and mercury is that recent years have seen a dramatic rise in diagnoses of autism, as well as an increase in the use of thiomersal-based vaccines. However, to make this interpretation is to fall victim to a common logical fallacy cum hoc ergo propter hoc (Latin for "with this, therefore because of this"). It is more commonly known as mistaking correlation for causation.

In my research methods course, I tell my students that I have incontrovertible evidence that consuming chicken decreases murderous rage. You see, I conducted a study in which I examined statistics published by the U.S. Federal government's Department of Agriculture and the Bureau of Justice. You can get the data yourself here and here. What you find on the one page is that chicken consumption has increased from the period between 1996-2005. On the other page, you find that murder rates have been sharply declining over that same period. Thus, eating chicken somehow reduces murder. Right?

Here is a graph of the relationship. You can see a clear negative relationship between per capita chicken consumption in pounds, and the murder rate per 100,000 people. The correlation is strong, at .84.

Of course, this is all a bunch of horse manure. Why? Because especially over time, many things increase or decrease, such as the amount of chicken people eat (due to health concerns) and the murder rate (due to a decrease in the use of crack cocaine). If you took the correlation between my age during the years and either of these variables, you would find significant correlations because my age increased while chicken consumption increased or murders decreased. Just because something correlates with something else doesn't mean one causes the other.

Likewise, the use of a vaccine and changes in the diagnostic category of autism (i.e., more children mistakenly diagnosed before as mentally disabled now receiving the "correct" diagnosis of autism) can make it look like there is a causal relationship between the two, when in reality there is only a coincident relationship.

The problem I have is that far more people probably respect and follow the flawed logic of the former playboy playmate of the year than doctors and scientists at the National Institutes of Health, the Center for Disease Control, and the World Health Organization. These parents might avoid vaccinating their children, who may then acquire a disease like encephalitis, which could permanently damage the child's brain.

Remarkably, in this article, McCarthy writes that her child has recovered from autism and is developing normally! After lambasting the medical establishment for not rushing to her door to inquire, she attributes her child's recovery based to the dietary and socialization regiments.

Now I'm no expert in autism. What I really think is happening here is that children who are completely normal are being diagnosed as autistic when they are just going though a stage in which they are not developing 'normally.' They grow out of this stage and end up normal people because they were always normal, but that a frenzied crew of 'experts' have rung the alarm bell over autism and that many children are being misdiagnosed as autistic when in reality they are just developing on a different path than other children.

Autism is not cancer or HIV in which you can take a biopsy or blood sample and know to a high degree of accuracy whether the person actually has the disease. (But see my former post on problems with this in respect to HIV). Autism is nosologized as a set of behaviors that must be interpreted by doctors and parents, and there is no way of seeing autism in a microscope or on an assay. So in a culture of fear over raising children fueled by experts wanting to be experts (McCarthy being one of them as the author of a parenting guide), you end up with 'experts' who have made virtual careers over developing dietary interventions, intervention schemes, and the like, which low and behold work for children who never had autism in the first place, and were just kids going through an unusual developmental trajectory. These diets and regiments may or may not work for those who truly have the affliction of autism, but they always work 100% of the time for normal kids misdiagnosed with autism.

Don't get me wrong - I'm not denying that autism exists, and I have seen many children diagnosed with autism. A difficult child myself, I used to bang my head on the ground and had a strange fascination with the drain spout of the washing machine, which would fill the basement sink with bubbly water. My mother, who is a social worker trained to diagnose mental illnesses, often says I would have been diagnosed with autism. True, had I not been born in 1976, but in 1996, at the height of the epidemic.

In sum, I don't mean to belittle McCarthy or her family's experience. I am sure these years have been difficult for her and her son. But I think that people in the limelight should realize that the mass of people may take the wrong message. Do we need children dying of rabies because their parents are afraid of vaccinations? I think not.

Can environments be made smarter?: Building a better bin for recycling

We all have THOSE objects in our life, objects that frustrate, defy, and annoy us. My frustrating object is the cable tv box. When I want to turn it on, I never know which of two buttons to press, because depending on how the television was turned off, one or the other button won't work. Typically, I can't remember how I turned the television off. So half the time, I press the wrong button, then need to get up and walk over to the television to turn it on physically. A minor itch, but I find it infinitely annoying. I believe we all have those nagging itches that end up annoying us more than the real problems we face in life.

The problem with the remote is one known in the psychological literature as object affordances. An affordance is a physical aspect of an object that provides obvious cues as to how the object should be acted upon. Hanging strings afford pulling behavior, while fixed buttons afford pushing behavior. Some objects have obvious affordances, such as a door whose handle is designed so that it is clear whether you push or pull it. Others have not-so-obvious affordances, such as my remote, or my telephone at work (it's been three years and I still can't figure out how to forward a call), or my bank's online teller system (which is ridiculously complicated so that I can never sign into it correctly).

We interact with objects on a daily basis, but rarely reflect upon how well objects are designed to afford a desired behavior. There is a whole field of psychology about this issue which is known as ergonomics. People who study ergonomics examine aspects of the design of objects that improve their usability. A classic example I am using right now is the QWERTY keyboard. The keyboards we all use today were designed on ergonomic principles. Back in the days of the dinosaurs, when people would actually use manual typewriters, a problem would arise that commonly used combined letters like "-ed" would cause a jam of the typewriter. Note that in the alphabet, e and d are next to each other. The swinging letter e would strike the swinging letter d and would cause a jam. To avoid this, the American inventor Christopher Sholes designed a typewriter in which commonly combined letters would be spatially displaced on the keyboard, so that with the QWERTY keyboard, e and d were separated by a number of keys so they would not interfere. Unfortunately, however, the QWERTY keyboard actually serves to slow people down in their typing. Now that typewriters have gone as extinct as the dinosaurs, better designs exist, but the fact that so many people are used to the QWERTY design, it remains like a vestibular organ, useless but pervasive.

Humans design many artifacts, such as QWERT keyboards, desks, lamps, and monitors. One artifact that exists in our world are receptacles for disposing waste. Any economist would claim that humans are fundamentally consumers, yet an unintended byproduct of consumption is disposal. We drink a bottle of water, and subsequently must dispose of the bottle. In the second half of the 20th century, the idea of recycling became commonplace, and many institutions and municipalities have developed recycling programs to help reduce the amount of waste that gets buried in landfills. According to the EPA, the average american produces 3 pounds of trash per day. An unknown proportion of this trash consists of recyclable material such as bottles or cans that ended up in the general waste stream. Some of this material may be carelessly thrown out because people did not notice a recycling bin nearby.

In a study I recently submitted to a journal, my co-author Michelle Verges and I began thinking about the perceptual affordances of recycling receptacles. I had noticed that in my office building, there were two types of recycling bins. One type had a wide opening at the top and looked pretty much like a trash can except for the words "Cans and Bottles" on it. Another kind had a lid cover with a small hole cut in the center that was narrow enough to accept bottles and cans. The first type with wide openings contained about as much trash as your typical trash can. People may have mistaken the recycling bin as a trash can. The second type with a narrow hole contained only recyclables. This got Michelle and I to wonder whether it be the case that recycling bins might be designed to be smarter (by improving recycling compliance) or stupider (by reducing compliance rates).

Being an experimentaholic, I aimed to find out the answer. First, I secretly went around my building and manipulated the lids of the recycling bins. See the figure below. The bins were identical except for the presence of the lids. Half of the bins were manipulated to look like the photo on the left, with no lids, while half had the lids present as in the photograph on the right.


I went around twice a week measuring how many bottles or cans were deposited in each of the three bins for four weeks. At the end of the time, I tallied the results and found that with the condition on the left without lids, the recycling compliance rate (i.e., the proportion of recyclable cans and bottles deposited in the recycling bin) was 57%. However, with the lids present, the recycling rate shot up to 93%. The likelihood that this effect could be explained by chance is over 1 in 1,000,000.

So I have been going around taking photographs of smarter and stupider recycling bins. Here is a small gallery, of which I will increase over time.

1. SEPTA's Market East Station

This is a dumb design for a recycling bin. First, the sign is ridiculously small. Although it says RECYCLABLE, NEWSPAPER ONLY, people simply use the bin as a trash can.

While this one had some newspapers in it, there was also a plastic cup, a plastic bag, and a glass bottle. (I was rooting through it. All this education and I end up picking through trash...amazing).
Perhaps the problem is that the recycling bin looks too much like the trash can, and the heuristic that GREEN = RECYCLING is not yet very standardized or widespread (some of the trashcans at the very same station were the recycling bin above without the little sign. No wonder people mistake recycling bins for trashcans and vice versa!



2. Swarthmore Train Station

Swarthmore Township is a wealthy township where Swarthmore College is located. I recently went there to meet a colleague, and I spotted a recycling bin.


Here are individual pictures of the two recycling bins, and the contents. As you can see, the lids afford recycling paper or bottles by being a much smaller hole than the hole in the SEPTA train station.

Apart from a plate, a piece of plastic, and a piece of paper, everything in the recycling bin was appropriate for that bin.

Here is the newspaper bin:

Apart from the plastic bag, everything inside is newspaper.

The key however is not what is IN the recycling bin, but rather what WASN'T IN the adjoining trash can. There were no recyclable materials (cans, bottles, or newspapers) in the trash can.


3. Patco Station:

You don't need to buy special recycling bins in order to have high recycling rates. An ordinary trashcan lid, properly cut, makes a fine recycling bin, like this one spotted at the Camden, NJ PATCO train station:


4. Reading Terminal Market:

In order to increase recycling, why not make a bin that looks like a bottle? Although the study I completed does not speak to the effectiveness of this particular recycling bin, a look inside the trashcan next to it revealed several bottles and cans, which may indicate that people might simply be confused by what the object actually is (It could just be a plastic statue of a soda bottle to indicate that yes we sell drinks here.)


5. Japan

My favorite recycling bin was photographed by my friend Jeff Mosenkis in Japan. It is a frog. At least it is somewhat rewarding to shove a paper down a frog's throat if the news that day was bad. Unfortunately, though, my colleague Michelle is deathly afraid of frogs.

My Japanese colleague Etsuko writes, "The Japaense writing on the frog says "Kae--ru Box: For Newspapers and Magazines Only". The frog is pronounced as Kaeru in Japanese. With the same spelling in Roman letters, but with a different intonation and a Chinese character, Kaeru also means return. So, they are using a pun here for the recycling box."



Feel free to send me some pictures of your very own favorite recycling bins! I will post them here and have an expanded gallery.

Things I have had to do to do experiments

I was talking to my friend Michelle the other day about all the various things I have experienced on the way to gathering data for research. Lately, I've been watching a lot of Discovery Channel shows about various odd and dirty jobs people have, and also those shows about those crazy academics who go out in dangerous waters infested with killer jellyfish. It makes me realize, wow, I'm glad I wasn't stupid enough to choose a topic that almost kills me. But I have had my moments. Here are a few:

The peeing baby incident: That time when I was conducting research on infants' vision, a mother had to change her baby's diaper. In the midst of doing this, I turned to give the mother privacy and was working on my computer. Suddenly, I felt this weird wet sensation down my back and turned. Yup, you can fill in the rest of this story, but I was on the receiving end of a 6 month old's golden shower. I wonder if this baby (who must be about ten years old now) knows that he pissed all over some poor grad student at Chicago.

The vomiting RA: One time in Chicago, I had an experiment where I needed a confederate, someone who is pretending to be a naive subject but is actually in on the game. My RA came in the lab on a Saturday morning reeking of bar (stale cigarette smoke, cheap beer). She was still drunk. She apologized, and just as the subject showed up, vomited into her hands, which seemed to make things worse, spraying the flow and all over me and my laboratory. Just as the subject was coming in. Needless to say, she didn't last long after that.

The forgotten subject: This one didn't happen to me, but I caused this one to happen. One time, I had a friend of mine come in for an experiment in which the participant decided whether a particular fish was a member of category A or B on a self-running computer program. You see examples of fish on the screen and have to classify them as A fish or B fish, until you get 25 correct classifications in a row, at which point the experiment ends. I started this friend of mine, then somehow got distracted and forgot about him. Most people got the 25 correct in a row in about twenty minutes. Five hours later, I walk into the room for another reason, only to find my friend still at the computer, head in his hands, classifying fish. He got up and started screaming that he was going to Fing knock my Fing teeth out of my Fing mouth if I Fing make him Fing classify Fing anotherFing one of these Fing Fing fishes. I actually had to edit that - he said it with a lot more F bombs. He never let me forget that fish experiment. I think he is still scarred.

Chimp piss: When I was in Japan, I visited the National Primate Research Institute, where they have chimps. While watching one experiment, a baby chimp climbed to the top of his cage. I was about two feet away from him. He then let forth a violent spray of urine, covering me. Interestingly, that was the day I actually peed my own pants the next day, a story you can read about here.

Baby vomit. I was holding a baby for my experiment and it burped, then a little swish sound, and that familiar warmth down my back. I gotta stop working with babies!

There are probably other stories I have locked in the vaults of memory. I'll post any if I remember. Always remember - Don't due this at home. We're what you call, "professionals."

Overheard

I was talking with Matt, a friend of mine, last night. We were speaking about those people who are simply oblivious to the fact that they are completely obnoxious. In the course of the conversation, he said...

"You have a real problem when the biggest problem you will have to face in your entire life is you."

I have to say, never have truer words been spoken.

Finding the missing piece

Summer is time for love, and I offer you an analysis of the probability of meeting your soul mate. In his Symposium, Plato writes that people were originally both male and female. To prevent them from acquiring the power of the Gods, Zeus cut them in half. Life then became for humans a search for the other half that was lost, in order for them to once again attempt to ascend Mount Olympus.

It is a pretty story, and one that resonates with many a New Age follower’s conception of love. Even if it doesn’t quite jive with reality. But why not?

The reason once again has to do with probability. There is a well known problem in the statistics literature called the Birthday Paradox. Basically, the paradox questions, “How many people do you need to put into a room to get a 50% chance that two of the people have the same birthday?” The answer to this is 23. Therein lies the paradox – this seems like a very small number. Most people intuitively think that one needs to have 365/2 or 183 people in the room. But that intuition is wrong. The true formula is as follows:

N = .5 + SQRT((.25 + 2 * 365 * ln(2))

I would like to generalize this problem to the question of finding one’s soul mate. Specifically, the question I address is how many people would you have to include in a room for there to be a 50% chance that any two people in the room were once joined at the hip before Zeus took his shears and sliced them apart? Now, this assumes that the people in the room were randomly selected from the entire world population, which is approximately six billion people. The answer to this is simple, and follows the formula above:

N = .5 + SQRT((.25 + 2 * 6,000,000,000 * ln(2)) = 91,202

Wow! It would take a room of 91,202 people for there to be a 50% chance that any two people in that room were actually soul mates. One would have to have a pretty big room, perhaps as large as this room, which fits over 100,000 people.

Imagine a speed dating service in which you have five minutes to talk with every other person in this room. For those two lucky halves to actually have a chance to meet, the speed dating round would have to last for 91,202*5 minutes, which comes out to 316.67 days. All for only two of those 91,202 people to meet. This says nothing of the 91,200 people who leave Michigan Stadium brokenhearted or satisficing with someone who is not their other half.

But that doesn’t help you, dear reader, who doesn’t care about any two people encountering their soul mate, but rather about the probability that YOU will meet your soul mate. Well, the problem is that to calculate this, one would require a supercomputer that can handle a hell of a lot more decimal places than my humble Dell laptop. Needless to say, you would need a room about as big as this place to have a 50% chance of meeting your other half.

What does this tell you? Well, quite simply, you have about as much of a chance of meeting your other half as you do winning the powerball lottery. Either that, or the search for love isn’t a search for that one soul mate that Zeus cut from your side, but that any of a number of possible other halves fit approximately well enough that they can serve as soul mates. I tend to believe this is the case, because I know many a person who has claimed to have met their soul mate, and I know the probability of this actually occurring has about a snowball’s chance in hell. And whether or not I believe in soul mates matters very little. I do believe in probability!

But I tend to be hopeful. And I am a romantic who enjoys Greek mythology. I know my other half is wandering around out there. Of this I am certain beyond any statistical doubt. Whoever she is, I know she would appreciate my calculation of the infinitesimally small likelihood that we would ever meet.