Thursday, July 12, 2012

TL;DR - Relative Benefits From Religion Is being religious a good thing?  Previous research has found that people who are more religious tend to have better social relations, psychological adjustment, and even better health.  Gebauer and colleagues, however, found that the strength of these correlations can vary depending on the country a person resides in.

For the study, they used people's responses to questions for a popular European dating website, eDarling.  (Note that while this is self-report data--and self-report data on a dating site, at that--it's unlikely that there are going to be any systematic biases in reporting by country.)  The average correlation between religiosity and social self-esteem or psychological adjustment is on the order of .1 (not huge, but as a general rule there are no huge effects in social psychology).  This varied quite widely across the countries looked at, though, with more atheistic countries such as Sweden and the Netherlands having essentially no correlation, while the much more religious Turkey had a correlation of .2. 

So maybe it's less important how religious you are, as much as how culturally normative you are.

Jochen E Gebauer, Constantine Sedikides, & Wiebke Neberich (2012). Religiosity, Social Self-Esteem, and Psychological Adjustment: On the Cross-Cultural Specificity of the Psychological Benefits of Religiosity Psychological Science, 23 (2), 158-160 DOI: 10.1177/0956797611427045

TL;DR - This may be my last post...

Psychological Science, February 2012 -- "Saving the Last for Best: A Positivity Bias for End Experiences," Ed O'Brien & Phoebe C. Ellsworth.

...Okay, probably not, but maybe now you'll like it better.  We've known for a while now that how something ends can alter someone's evaluation of it (c.f. Redelmeier & Kahneman, 1996), but O'Brien and Ellsworth found that simply highlighting the fact that something is the last makes people appreciate it more.

Wednesday, July 11, 2012

TL;DR -- She's Just Not That Into You

Psychological Science, February 2012 -- "The Misperception of Sexual Interest," Carin Perilloux, Judith A. Easton, David M. Buss.

As every human knows, it can be hard to know when someone likes you.  We end up devoting a lot of cognitive effort (and song lyrics) to figuring out who would like to have sex with us, and dealing with the consequences of these beliefs.

In this study, Perilloux and colleagues set up a speed-dating situation, while also having each participant provide various ratings (including attractiveness and sexual interest) of each person they met, as well as self-ratings.  This way, they were able to contrast each partner's perception of the other and see how well they matched, or mis-matched. 

They found that men tend to overestimate the sexual interest of women, but that women tend to underestimate the sexual interest of men.  Also, the more attractive a man is, the worse his estimates of interest get, this despite the fact that women tend to also have more genuine interest in more attractive men.  When a woman is rated as more attractive, she's more likely to be misperceived as displaying interest in a man.

So far, so good.  This is a pretty interesting finding, and has implications for understanding complex behaviors such as rape.  However, the researchers try to explain the findings using an evolutionary framework, which I find unnecessary. 

Objection number one: they looked exclusively at an undergraduate sample from the University of Texas (mean age: 18).  You could argue that, as people in their reproductive primes, this sample should be most representative of our evolutionary heritage.  But still, American undergrads are poor representations of the majority of humans on the planet, living or dead.  I always like to see some extensions to different populations before I'm comfortable with an evolutionary hypothesis.

Objection number two: the evolutionary theory isn't needed.  For instance, they try to explain why more attractive women would be more likely to be misperceived as interested by attributing this to an evolutionary bias based on the correlation of fertility and attractiveness.  But this could also be explained by, essentially, wishful thinking.  Our desire for something to be so can influence our estimation of its likelihood.  A cognitive explanation can substitute for an evolutionary one.  And likewise with the difference in over-/under-estimation between men and women: this could be a difference in set points based on the level of sexual interest in the individual him/herself.  Or the finding that more attractive men overestimate more (over-overestimate?): well, as it's pointed out, they also have more success than less attractive men, so could this just be driven by learning?  More frequent reward leads to greater perception of interest, more frequent punishment leads to less?

The authors need to do a better job setting up the kind of background necessary for an evolutionary explanation to be sensible.  Is accuracy of perception of sexual interest linked with differential fitness?  It's not really clear; it's briefly alluded to and glossed with citations -- all of which are connected to one of the authors (Buss).  But this is a prerequisite for making a claim that a trait has evolved!

Overall, there's nothing in this study that couldn't be explained through more fundamental cognitive or learning mechanisms.  Does that mean an evolutionary explanation is wrong?  No.  It just needs more convincing evidence.

Wednesday, July 4, 2012

TL;DR - Teacher Experience Matters

Science, March 2, 2012 -- The Effects of Experience and Attrition for Novice High-School Science and Mathematics Teachers, Gary Henry, C. Kevin Fortner, & Kevin Bastian

There's a lot of things wrong with the public education system in the US, but one of them is its ability to retain high-quality teachers.  Due largely to anemic rates of compensation, a student in public school is likely to encounter either a bright, motivated young teacher -- who disappears in a few years -- or an older teacher who may or may not be that effective.

What does this system mean for students, though?  We already know that teacher quality can play a large role in determining student success, but how much does teaching experience contribute?  If we just look at the number of years that a teacher has been around, we definitely see a positive correlation with student success.  However, is this due to the experience gained by those more senior teachers, or is it just an artifact of less competent teachers dropping out of the profession earlier?

Henry, Fortner, and Bastian attempted to address this question in a large-scale retrospective study looking at teachers in North Carolina.  Their sample included end-of-year test scores for hundreds of thousands of students, linked with thousands of teachers across several math and science (STEM) courses, as well as several non-STEM courses.  In the analysis, they were able to separate and compare the teachers who would and would not continue teaching after five years.

One thing they found was that teachers who remained past five years were more effective than teachers who dropped out earlier, supporting the hypothesis that lower-quality teachers leave the profession earlier.  But they also found a clear upward trend over the years for the other teachers; over the course of five years, the test scores for the teachers' classes increased reliably.  Experience does matter.

But all experience is not equal.  While there was a general upward trend for all teachers, physics and chemistry teachers demonstrated the greatest increase.  How about those non-STEM teachers?  They actually showed much smaller gains in efficacy over the years, essentially leveling out by year 3.  It should be pointed out that this doesn't mean the non-STEM teachers were any worse (or better) than the STEM teachers.  Comparing physics scores to English scores is one of those apples/oranges situations.  So it's not clear why there was this difference across disciplines.  Is there something about STEM courses that makes hands-on experience more valuable than for non-STEM courses?  Or is there something about the teacher training that the teachers receive?  Unfortunately, we can't really tell from this study.

Regardless, it's clear that the sort of rapid turnover that we're seeing in public schools is doing a big disservice to our students.

Friday, June 8, 2012

TL;DR -- Spreading Cash Around the Developing World Science, Feb. 24, 2012 -- "One-time Transfers of Cash or Capital Have Long-Lasting Effects on Microenterprises in Sri Lanka," Suresh de Mel, David McKenzie, & Christopher Woodruff.

International development and philanthropy have long been a big interest of mine.  But often practices in these areas are driven more by emotion and intuition than by sound research.

This study examined effects of granting small amounts, either in direct cash or in equivalent resources, to small business owners (in which the owner was the only employee) in Sri Lanka.  This is not microfinance, as practiced by Kiva or the Grameen Bank, but is similar to the approach taken by GiveDirectly.  However, the effects of this strategy, and especially the long-term effects, have been poorly understood; does an infusion of cash actually contribute to the success of the business and the survival of the business owner?

Five years after the researchers initially randomly distributed large ($200 equivalent) or small ($100 equivalent) amounts to small business owners, they returned to evaluate the survival and the financial health of the businesses.  What they found is that those who received initial grants did better in the long run -- they were more likely to still be in business, and their businesses were more profitable, as compared to control businesses ...but only for men.  For women, those who received grants fared no better (and, in fact, numerically worse) than those who had not received grants.

This is unsettling news.  In fact, many organizations, such as Grameen, target their approaches based partly on gender, focusing on helping out women over men.  This research suggests that, despite good intentions, this practice may be ineffective.  But why were no benefits found for women?  This study can't fully answer that question, but the authors speculate that many of the women redirected the funds (or cashed out the resources) to their households, instead of investing in their businesses.  This makes sense, considering that the businesses run by women were only about half as profitable as those run by men; the short-term gains may have overridden any long-term planning.  Factors other than gender, such as base profitability, may interact with the intervention to determine success.

Of course, there are limitations to this research.  The outcome measures were exclusively economic, but it's possible that the women who received the grants got some benefit to other measures, such as health.  It's also not clear how well these results would generalize to other regions.  Is there something specific to the cultural or economic environments of Sri Lanka that lead to this gender disparity?  But on the other hand, it's also very heartening to see that such a simple intervention can lead to durable change.

Suresh de Mel, David McKenzie, Christopher Woodruff (2012). One-time Transfers of Cash or Capital Have Long-Lasting Effects on Microenterprises in Sri Lanka Science DOI: 10.1126/science.1212973

Two on Two

There are very few things that are a surety in life, but one is this: everybody poops.  So what do psychologists have to say about this most basic of functions?  In the latest issue of The Psychologist, Nick Haslam takes us on a whirlwind tour of psychological theory and research into human excretion, from its presence in the symptomatology of various mental disorders to its role in social relations and gender roles.  Unfortunately, this is a topic that has been understudied in psychology, so the literature is kind of scant and disconnected.  However, ESPN happens to have a more focused look into the same topic that reveals both the physiology, as well as the sociology, of crapping one's pants.  A taste (poor choice of words):
The sphincter has the final say in these matters, and it is controlled by a unique double ring of muscle tissue that acts like a clip around the bottom of an inflated balloon. The outer ring is made up of voluntary muscle fiber that's under our conscious control. But the inner, more dominant ring is made up of involuntary tissue and regulated by the independent neurological gatekeeper found in the reflex centers of our spinal cord. The battle for control over the sphincter, then, is a smaller version of the constant tug of war between the sympathetic and parasympathetic divisions of the nervous system that athletes deal with when pushing their limits.

Tuesday, May 29, 2012

TL;DR - New Wave Antidepressants

    Scientific American, March 2012 -- "Lifting the Black Cloud," Robin Marantz Henig

    The current class of antidepressant medications, which focus on serotonin and norepinephrine, have limited effectiveness and come with a range of negative side effects.  As a result, people suffering from depression often find themselves bouncing from medication to medication, with more or less effectiveness.  Henig descibes several novel drug targets that are under investigation, and which promise a future of more choice, and better results for the depressed. 
    Ketamine is one such substance, which shows promise in speeding neural regeneration in the prefrontal cortex, reducing or reversing the neural atrophy there that often is associated with depression.  Acetylcholine is another neurotransmitter that shows promise as a target; ironically, it was one of the first systems targeted for study, but was largely ignored after serotonin showed so much promise.  Other drugs target nicotinic repceptors, and seem to be effective at stimulating neural growth in the hippocampus.  Finally, another novel research angle is to focus on inflammation, which is often associated with depression.