The Evolutionary Psychology of Andrea Yates

The Texas woman who drowned her 5 children in a bathtub has been on my mind nearly non-stop since my husband, Mr. Field Notes, was told by his new psychology prof that evolutionary psychology has nothing to say about the case, because her genes died with the kids, whereas the other perspectives of psychology do.

I have been trying to keep from going bananas about it. After all, he is only taking the class to satisfy a dumb prerequisite required for what he really wants to study. And it's only a dumb requirement because he already has a much larger knowledge of psychology than most students who take intro retain even after 6 months.

So anyway, he started taking an introductory psychology class online through our local community college and I didn't have high hopes that it would actually be a good class, and I agree that he should just do the minimal effort required to get an A and leave it at that.

But...

When the prof so summarily dismisses my field's perspective so early on, it sort of slams the door on that perspective being seen as valuable from there on out. I just don't like the foundation it sets for the rest of the class and he can, if he chooses to, defend the perspective and show that it actually has some value, not to mention increase everyone's knowledge. I don't know if he will speak up in the class discussion forum where it came up, but I kind of hope he does.

If I were him, I'd argue that Andrea Yates killing her kids is an example of female infanticide and that under certain circumstances, killing your own progeny can increase reproductive success. It wouldn't at first glance seem so, but evolution is not as simple or as black and white as it appears.

A woman who has a lifetime of reproductive years ahead of her and has a baby that is unhealthy, sick or disabled, or for whom she is unable to care for due to life circumstances such as poverty, lack of support, or ill health herself (including mental illness), may 'choose' to kill that child (or children) and try again for a healthy one or postpone having children until her situation changes so that when she does have another child, the child will have a better chance of actually surviving long enough to reproduce. By doing so, she cuts her losses and saves wasted energy.

Rarely do other animals continue to care for sick or disabled offspring. And, there are examples of animals, primates even, that postpone their reproduction until their circumstance becomes more favorable for reproduction. Tamarins are a great example of this. Often, the reproductively mature offspring of these small South American monkeys stay with their parents and take care of their younger siblings instead of moving away to start families of their own. They could move away from home, get 'knocked up' and try to take care of those babies on their own in an area where they cannot adequately defend enough territory to have food to eat and a safe place to sleep, but they don't. And they don't go off to have those babies, realize they made a mistake, kill the babies and try all over again when they can find a place with food and shelter. Instead, they don't even bother moving out; they stay put and become adult babysitters. They invest in the genes they share with their siblings and bide their time until they can successfully raise a family of their own.

We humans don't seem to be very good at delaying reproduction until better times even with access to condoms and birth control. There are plenty of news reports of babies found in the toilet and in garbage bins, and of course, humans have plenty of abortions. There are also plenty of examples of women who wait until they're done with school and have a career and an established social support system before they start a family (and sometimes they wait a little too long and find their fertility has dropped, making this strategy not entirely foolproof either).

My point is that people kill their own kids, more often before they are even born, and while it seems counter to evolutionary theory for them to do this since it kills their genes, it doesn't kill their ability to produce kids. They can still reproduce in the future and if being motivated to kill your kids under the right circumstances means that your reproductive success isn't zero, i.e. you still have a child that survives to reproduce later, then the genes that contribute to that motivation haven't been selected against. The only thing that would truly be inexplicable from an evolutionary perspective is why people would get a vasectomy or have their tubes tied before they ever reproduce. And even that can be predicted by evolutionary theory if those people tend to contribute to the reproductive success of their relatives, with whom they share many of the same genes.

In any case, evolutionary theory would predict that a woman would be most motivated to kill her own children if:
* They are severely sick, injured, or physically or mentally disabled to the point of being unlikely to reproduce as adults,
or
* She lacks the financial, emotional or social resources (social support) needed to effectively care for them,
and
* The woman is young enough to have a better chance of successfully reproducing later than if she continued to care for the child/children.
In such cases, the benefit could outweigh the cost. For the behavior of Andrea Yates to be a perfect example of this, she would have had to be younger than 45 (an age at which there is a significantly reduced chance of being able to become pregnant) and be poor or depressed or socially isolated or have ill or disabled kids. She was 36 at the time, young enough to be able to reproduce again, and from the Wikipedia account on her, sounds as though she had little social support to help care for the children, and was convinced the children were defective.

Steven Pinker, a respected evolutionary psychologist, argues in his book How The Mind Works, that post-partum depression is a mechanism that motivates a woman to kill her newborn in just these circumstances. It has been said that Andrea Yates had been experiencing post-partum depression.

I don't think Andrea Yates is a perfect example of the 'kill your kids to bide your time and reproduce again when conditions improve' strategy, but she does fit the bill for an individual who would be expected to be motivated to do so.

Flu during pregnancy raises risk of schizophrenia

With all the talk of swine flu, or whatever they're calling it these days, I couldn't help but recall some research I came across years ago. It found that pregnant women who contract the flu have an increased risk their child will develop schizophrenia later in life.

Schizophrenia is a serious psychosis — a mental illness characterized by disordered thinking — that can include visual and auditory hallucinations, paranoia, and delusions. In colloquial language, it means you're insane. Schizophrenia affects about 1% of the U.S. population and can be seriously debilitating, requiring institutionalization in severe forms. You may recall the movie A Beautiful Mind in which actor Russell Crowe portrayed a man with schizophrenia. The symptoms don't usually appear until a person is around 20 years old.

The link between maternal flu infection and schizophrenia was published by Dr. Alan Brown, a Columbia University psychiatrist, in 2004 in the Archives of General Psychiatry. His research team looked for antibodies to influenza in archived blood samples from 64 women whose children developed schizophrenia as adults and a control group of 125 women whose children did not. Women who had higher levels of influenza antibodies in their first or second trimester of pregnancy had offspring who were 3 to 7 times more likely to develop schizophrenia.

Brown calculated that if the women had not had the flu during pregnancy, 14 percent of the schizophrenia cases could have been prevented, an effect he calls potentially enormous.

Although researchers do not know the mechanism of action, many think a certain protein released by the mother’s immune system in the wake of a flu infection goes on to harm the infant's developing brain. A flu infection stimulates the release of an immune system protein called interleukin-6, which in normal amounts helps the immune system do its job. However, the release of abnormal amounts of IL-6 is associated with autoimmune disorders such as allergies and asthma, rheumatoid arthritis, lupus and more. In the wake of a flu infection, the immune system can go haywire. The normal result of fever, inflammation and secretion of glucocorticoids like cortisol, aka the 'stress hormone,' can go bananas and cause the immune system to destroy good cells — possibly in this case of schizophrenia, brain cells in specific regions of the brain of the developing fetus.

Given the known genetic links to schizophrenia, it is also possible that an inherited predisposition to an abnormal immune system reaction in the wake of flu is another risk factor. After all, the vast majority of women who get the flu during pregnancy do not have children that grow up to have schizophrenia. According to Brown's research, the overall risk of schizophrenia from flu is small — 97% of children born to women who got the flu while pregnant will not develop schizophrenia. But what if you have inherited a predisposition to over-react to the flu? Perhaps your risk of having a child with schizophrenia goes up — way up.

This is certainly something they arouses my concern given I have a family history of autoimmune disorders in my immediate family. My mom is a walking advertisement for screwed up immune system and my little sister developed an autoimmune response to the flu when she was 6 — a rare condition called ITP that put her in the hospital for a week. Then there's a more distant relative who actually had schizophrenia. Needless to say, I have already started taking precautions at work and will happily become a hypochondriac washing, antisocial freak just to be safe.

Regardless, it is interesting that schizophrenia may yet turn out to be a partially communicable disease.

By the way, if you are sick, please cough into a tissue or your sleeve and not your hands!!
If you put those germs on your hands you spread em!

Is autism caused by vaccines? The straight truth.

More and more these days I notice parents who refuse to have their children vaccinated for measles, mumps and rubella because they have heard that the vaccine causes autism. They are all shockingly uninformed, but don't realize it. Part of the problem lies in the fact that they don't realize the one bit of highly publicized research evidence that supports the autism link is riddled with multiple and damning problems. And just this week, it got a lot, lot worse.

According to an investigation by the Sunday Times newspaper, the doctor who sparked the scare over the safety of the MMR vaccine, Andrew Wakefield, fabricated the data that created the appearance of a possible link with autism. He lied. You can read the full article here.

Compared to lying, the other problems with Wakefield's research seem minor in comparison. But nevertheless, even if the results were not made up, the fake-o numbers still do not in any way warrant the autism hysteria that has erupted over vaccines.

And the effect of the hysteria is significant. After the publication of Wakefield's research in 1998, rates of vaccination fell from 92% to below 80% in the UK, according to the Times. And in just ten years, the number of confirmed cases of measles skyrocketed to 1,348 compared with just 56 in 1998.

Aside from the glaring problem with using fabricated data, the other problems with Wakefield's research are threefold, scratch that fourfold!

1. extremely small sample size: The research included only 12 kids!

2. relied on retrospective evidence: Rather than starting out with a sample of children who neither had autism nor had yet been vaccinated, the study used parents who reported autism symptoms after the child was vaccinated. In other words, the researchers relied on parents of autistic children’s memories of events — parents who were understandably upset and far from objective observers.

3. biased sample, i.e. not randomly selected: Almost half of the kids' parents were recruited by a lawyer who planned to sue the vaccine manufacturers. Even Wakefield himself received money to assist the case by finding scientific evidence of the link between autism and the vaccine. You can read more about that here.

4. conclusions overstated the data: The published article stopped short of concluding that there was a causal link between the MMR vaccine and autism. However, when Wakefield spoke to the press he made no such disclaimer. And to this day, outspoken celebrities jump on the bandwagon.

One reason some parents think vaccines caused their child's autism is the timing of diagnosis. The first signs of autism don't appear until around 18 months to 2 years of age, the same time period in which kids are vaccinated. It is this unfortunate timing that makes parents think the vaccines caused the condition. Another case of erroneous correlation = causation thinking.

If vaccines really were causing autism, you'd at least expect to see the incidence of autism rise and fall with the rise and fall of vaccination rates — but it doesn't. You can read the published research yourself here. The article also has an impressive list of other relevant research articles on the subject. I think it's pretty much overwhelming evidence that something other than vaccines causes autism.

Rainman: Does rain cause autism?

Of course not, but the results of a study recently published in the Archives of Pediatrics and Adolescent Medicine seem to indicate an association between autism and rain.

Specifically, the rate of childhood autism is higher in counties in California, Oregon, and Washington with greater precipitation.

According to the study's co-author, Sean Nicholson, who is not a psychologist but rather a public policy analyst, Washington counties west of the Cascade Mountains, get four times as much precipitation and had autism rates twice as high as those in the drier east.

The research made headlines in papers across the country, including our small community's newspaper. It makes sense too, if rain doubles the chance of autism, you'd think that's important information people should know about.

While the results of this study are interesting, it needs to be put into proper context. First of all, this is another case of correlation research. Two things being associated does not mean one caused the other.

Another cause for concern with this type of research finding is how it is that we're looking at incidence rates, not raw numbers. And this kind of number (rates) is very difficult for to keep in perspective.

If the rate of autism is doubled in rainy counties, what do suppose is the risk of any one individual developing autism in that county compared with one in a drier county? Twice as high, you'd say. But — you'd be wrong. Why? In absolute terms, about 1 in 150 people has autism. If the rate doubles, that means 2 in 150 people has autism. So, the rate of autism goes from 0.6% to 1.3% which is a lot, lot smaller than the 100% increase that gets reported.

Dang it. So much for statistical literacy.

Lately I've been paying a lot more attention to this issue since I received a special supplement to a peer-reviewed academic journal I subscribe to. The supplement, Psychological Science in the Public Interest, features a long article written by a team of very critical scientists who argue that the way health statistics are presented, oftentimes with the complicity of medical doctors, does an enormous disservice to the public and in some cases does actual harm by leading people (and doctors themselves) to make bad medical care decisions.

I'm only 3 pages into the tome, but I'm finding it very interesting and it has certainly helped me to put studies like this Rain + Autism one into proper context.

I'm not sure what public policy decision the autism study authors would make, but I wouldn't be surprised if they were downright idiotic.

Here's some evidence to support my hunch. They had presented early results from this data before as part of the Johnson Graduate School of Management's "Research Paper Series" which I'd bet is not a peer-reviewed journal. This is what they had to say about it (edited for brevity, and bolded to point out where the authors false make causal claims where the data is merely correlational):

"Autism ... one of the current theories concerning the condition is that early childhood television viewing serves as ... a trigger. Using the Bureau of Labor Statistics' American Time Use Survey, we... show... consistent with the television as trigger hypothesis, that county autism rates are also positively related to the percentage of households that subscribe to cable television. Our precipitation tests indicate that just under forty percent of autism diagnoses... is the result of television watching due to precipitation, while our cable tests indicate that approximately seventeen percent of the growth in autism... is due to the growth of cable television. These findings are consistent with early childhood television viewing being an important trigger for autism."

Now that an apparently respectable peer-reviewed journal has published this autism + rain link piffle, I'm left scratching my head and hoping that people don't monkey around and take this crap seriously.

Rain and TV viewing do not cause autism!

Is a 3-yr-old who eats paper normal?

She keeps eating paper. She's fine developmentally, she knows it's not food. Do you think she may have pica or is it just a preschooler thing?

Anytime paper and psychology intersect, you know I'm going to get excited!

According to the DSM-IV-TR, the diagnostic manual of psychiatry and clinical psychology, pica (diagnosis #307.52), is the "consumption of nonfood items, including dirt, clay, starch, ice, cloth, and so forth. Transient pica is very common in normal children, and may also be seen in about one-quarter of severely retarded patients. Pica may be seen in up to a third or more of pregnant women; it may also be endemic in certain culturally isolated groups, but is for the most part rare in otherwise normal adults."

Note especially this part: Transient pica is very common in normal children. Also, for someone to actually have a case of pica, the following DSM criteria need to be met:

• Persistent eating of non-nutritive substances for a period of at least 1 month.
• The eating of non-nutritive substances is inappropriate to the developmental level.
• The eating behavior is not part of a culturally sanctioned practice.
• If the eating behavior occurs exclusively during the course of another mental disorder (e.g., Mental Retardation, Pervasive Developmental Disorder, Schizophrenia), it is sufficiently severe to warrant independent clinical attention.

A developmentally normal three year old who eats paper occasionally is totally normal, i.e. it is most definitely a pre-schooler thing.

I think this question about pica is a good question because it relates to many things that are fun to think about: the culture of food, the definition of abnormal behavior in light of cultural expectations for behavior, and also a relatively new field in behavioral studies called zoopharmacognosy [Zoh-o-farm-uh-cog-nose-ee is how I say it].

Michael Huffman, a primatologist I would love to meet some day, perhaps at the Kyoto University of Japan in January when I'm in Kyoto, is one of the founders of the field. Zoopharmacognosy is basically the study of herbal medicinal use among animals. Primatologists like Huffman have discovered that monkeys and apes ingest substances that are not food because they have beneficial properties. These include charcoal, mud, the bitter pith of trees and various other things that are not normally eaten, including in the case of woolly spider monkeys and lemurs — plants that affect fertility.

Here's a brief synopsis of some non-foods that animals eat for health reasons:

• Aspilia plant leaves - chimpanzees - rids intestinal parasites
• Vernonia bush pith - chimpanzees - helps upset stomach
  
• fruit from the 'Monkey Ear' plant - woolly spider monkey - increased fertility
• leaves of Apulia leiocarpa & Platypodium elegans - woolly spider monkey - decreased fertility
• Boraginaceae trees - elephants - induce labor
• clay - spider monkeys - diarrhea treatment
• charcoal - colobus monkeys - counteract toxins in a highly nutritious plant
  

Note that some of these (leaves, fruit, etc) may seem like food, but they are not ingested frequently and they are apparently only sought out when the individual is sick.

The condition pica, even as defined by the DSM, may not be inherently abnormal or 'crazy' after all. Perhaps the child who eats paper senses a dietary deficiency in fiber. And maybe the pregnant woman who craves dirt or clay instinctively wants to cleanse toxins from her body to keep the fetus healthy. However, there is no doubt in my mind that some forms of pica — such as a French man who ingested $650 worth of coins — are clearly abnormal and dangerous to one's health. Pica is just one example of a healthy behavior that when taken to the extreme, is anything but.

For further reading:
Really Wild Remedies
Geophagy: Soil Consumption
By Watching What Animals Eat, Experts May Find New Medicines for People
Bite the Bullet: A man who ate bullets