26 May 2017

Testosterone and Decisions

Welcome back. One of the many TV ads I can’t avoid when I’m trying to get the news while stretching and exercising before predawn jogging is for a testosterone booster. I haven’t listened closely, but it appears that, if I buy and take the product, I’ll be able to run, climb mountains and fix plumbing. (Obviously, the advertiser didn’t see my blog post, Plumbing and Me.)

Although I’d normally ignore the ad as I do those for indestructible cooking pans, stop-any-leak tapes, where to take my latest invention and all the rest, there was a recent study that had me thinking about testosterone--not for me, for the blog.

Importance of testosterone.
(multiple websites)
Before telling you about that study, I’ll note briefly that testosterone is a hormone involved in regulating men’s sex drive, sperm production, bone density, fat distribution, muscle strength and mass, facial and body hair and red blood cell production. Females also produce testosterone, usually in relatively small quantities.

Testosterone affects physiology, brain development and behavior throughout life. The levels peak in adolescence and early adulthood then trend downward about one percent a year after age 30 or 40.

Estimated decline in male testosterone
production with age. (multiple websites)
Testosterone replacement therapy may prove useful for hypogonadism, a disease that prevents the body from producing normal amounts of testosterone; for aging, however, research has yet to show consistent, definitive benefits. Maybe more important, the therapy poses a number of potential risks from acne to heart disease and should be discussed with one’s health provider.

Cognitive Reflection Test

Earlier studies have linked testosterone with aggression and disorders associated with poor impulse control. In an effort to determine how the hormone influences decision-making processes, research collaborators from the University of Pennsylvania, Canada’s Western University, ZRT Laboratory and California Institute of Technology enlisted 243 men in the largest behavioral testosterone administration study to date.

Several hours after initial screening and application of a single dose of testosterone or a placebo in the form of an upper body topical gel, the participants took a battery of behavioral tasks. Of the tasks, only the Cognitive Reflection Test (CRT) was used for analysis.

The CRT is designed to identify one’s tendency toward either intuitive judgements or deliberate information processing. The test is simply three questions, each of which seems to have an easy answer. Upon reflection, the test-taker should find those first answers to be incorrect.

Cognitive Reflection Test (from www.aeaweb.org/articles?id=10.1257/089533005775196732) See P.S. for answers.
The participants took the CRT without a time limit and with the incentive of $1 for each correct answer and a $2 bonus for solving all three questions correctly. Because the CRT questions are mathematical, participants completed an additional math task as a control on math skill, engagement levels, attention and motivation. They also provided pre- and post-treatment saliva samples as checks on testosterone and to control for levels of other hormones that might influence cognition and behavior.

Testosterone’s Effect on Decision Making
Testosterone administration reduced CRT correct answers by 20% relative to the placebo group. The effect was robust, controlling for age, mood, math skills, treatment expectancy and 14 other hormones, and held for each CRT question. Interaction between treatment and response suggested that testosterone recipients gave correct answers slower than participants who received the placebo.

The overall conclusion is that testosterone increases confidence and reduces cognitive reflection. Where rapid intuition is useful, increased testosterone will boost performance; where deliberation is needed, testosterone might impair performance.

Wrap Up
Despite my lack of interest in TV ads for testosterone, a recent study by researchers from North Carolina, Chicago and Johns Hopkins universities confirmed the ads’ effectiveness. Analyzing data from 2009 to 2013 for 75 designated market areas in the U.S., they found each household advertisement exposure was associated with increases in rates of new serum testosterone testing and treatment initiation of about 0.7% every month.

I’m sure most of those men just wanted to improve their plumbing skills. Thanks for stopping by.

Example references on testosterone:
Study on testosterone and cognitive reflection submitted to Psychological Science journal: authors.library.caltech.edu/77049/
Article on study on ScienceDaily website: www.sciencedaily.com/releases/2017/04/170428154556.htm
Study on response to testosterone television ads in JAMA: jamanetwork.com/journals/jama/article-abstract/2612615
Cognitive Reflection Test in Journal of Economic Perspectives:
(Answers to Cognitive Reflection Test questions: 5 cents, 5 minutes, 47 days)

19 May 2017

Predator-Mimicking Moth

Make-believe cockroach from
Cyborg Insects post. (My wife
wouldn’t have read the post
if she saw a cockroach.)
Welcome back. Tell me. Be honest. Don’t you miss my insect posts? Not just the important ones like Entomophagy (consuming bugs) and Plastic-Eating Insects. I mean the fun ones like Millipede Photo Addendum (Giant African millipedes!) or Cyborg Insects or even Beetle News (dung beetles). I know it’s hard to choose from the 26 insect posts.

Buckeye butterfly from
Eyespots Photo Addendum.
(photo from www.insects.org)
Anyway, do you remember my post on butterfly and moth eyespots (Eyespots Photo Addendum)? Those eye-like markings on wings are likely a form of mimicry to deceive predators. Well, I’m back with bugs, because I’ve got an absolutely phenomenal example of mimicry. I missed a study on this one in 2006; I wasn’t blogging yet. But there was no way I could let the recent study slip by without fanfare.

Earlier Study of Predator Mimicry
Biological mimicry is found throughout the animal kingdom and can take different forms to appear dangerous or inedible or to draw a predator's attention away from vulnerable body parts (for the latter, see my post Fish Eyespots). Not often, however, does a species mimic its own predator, especially in both appearance and actions.

That’s what University of Connecticut researchers found when they studied how the metalmark moth (Brenthia coronigera) evades the jumping spider (Salticidae family).

Jumping spiders have acute vision, distinguishing prey, mates, rivals and enemies by shape, symmetry, presence of legs and wings, size and style of motion. They maintain their territory from other jumping spiders through ritualized displays, such as a male raising and waving his forelegs at the intruder.

The researchers observed that the metalmark moths perch on vegetation in a peculiar posture, raised forewings and twisted hindwings, so they look like the spider from front and back. To top it off, the moths move with short, rapid, jerky motions, in a manner similar to the spider.

Metalmark moth: A. Prepared specimen, B. Live moth in mimicking forewing (FW) and hindwing (HW) posture. (doi.org/10.1371/journal.pone.0000045.g002)

Through various trials pairing one jumping spider with one moth in a small container, the researchers found the metalmarks had much higher rates of survival than a control moth species, which exhibits no mimicry. When the moths and spiders were of similar size, only 5 of 77 metalmarks were caught, compared to 43 of 69 control moths. Many jumping spiders engaged in territorial displays after encountering a metalmark; there were no displays with control moths. In fact, the spiders began stalking the control moths soon after the moth was introduced in the container.

OK, that’s interesting, you say, but phenomenal? Here’s the rest of the story.

Recent Study of Predator Mimicry
Researchers from Taiwan’s National Sun Yat-sen University, the University of Tokyo and Queen Mary University of London went a step further, exploring the relative importance of the visual and locomotor signals the metalmarks use to deceive jumping spiders.

To determine whether the two forms of mimicry back up one another or serve different purposes, they tested the metalwork moth along with a moth species, which relies only on locomotor mimicry, and a control moth. Compared to the other moths, the metalmarks’ use of pattern, posture and jumping behavior allowed more time to escape and resulted in the lowest predation rates.

The researchers also tested metalmarks, whose eyespots were removed with watercolor brushes, and metalmarks, which were frozen in a territorial display or neutral posture. The predation rate increased when the eyespots were removed, and the spiders attacked significantly sooner when the moths were in fixed positions.

Wrap Up
The study results clearly supported the back-up signal hypothesis--multiple forms of mimicry deceive predators better. And here’s what you’ve been waiting for.

As in the earlier study, some spiders performed leg-raising displays with the metalmarks. At least some of those displays were attributed to courtships. The metalmarks did such a super job at mimicking their jumping spider predator, the spiders were actually courting them.

Thanks for stopping by.

-Earlier study of spider-mimicking metalmark moths in PLOS One journal: plosone.org/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1371%2Fjournal.pone.0000045 (video from study: vimeo.com/68928863)
-Recent study of spider-mimicking metalmark moths in Animal Behaviour journal: www.sciencedirect.com/science/article/pii/S0003347217300921
-Article on recent study on New Scientist website: www.newscientist.com/article/2128929-moths-disguise-is-so-good-spiders-love-it-instead-of-eating-it/

12 May 2017

Retail Pricing Strategy

Gas station prices,
April 2017
(photo by Vicki)
Detergent, $8.99; light bulbs, $7.99; ibuprofen, $4.99; hangers, $2.49; television, $499.99; video game, $49.99; smart watch, $199.95, men’s boxer briefs, $14.98; strip steak, $7.99/lb…must I go on? Oh wait. How about gasoline? Does anyone even see the 9/10?

Forgive me. Welcome back. Retail pricing is one of my pet peeves. (Surprise! I have lots of those.)

When I was about 10, I asked my father, who owned a retail store, why prices ended in 99 cents or 98 cents or 95 cents. Why didn’t he charge an even dollar? I don’t remember his answer, but it couldn’t have been very convincing as I’m still wondering. I finally decided to dig a little.

It’s Not New
Nowadays, pricing items slightly below the whole number goes by different names, most often psychological pricing or charm pricing.

Business historians haven’t been able to pin down when the practice began, though advertisements applying the strategy have been around since at least the late 1800s. 
Macy ad from 1880s (from www.nytimes.com/2009/02/08/weekinreview/08arango.html?)
Among reasons suggested for adopting the strategy are the obvious, to compete with other vendors, and one you’d never guess, to ensure the cashier would open the cash register to give change and not just keep the dollar. Although I can understand how cash registers, invented in 1897, might facilitate accounting and inventory control, I don’t see why the cashier couldn’t occasionally take the change from his or her pocket and avoid ringing the cashier bell. 

Ad for tombstone,
Sears Roebuck & Co.
catalog #110, 1900.
It Helps Sell More
As any business or marketing major can probably tell you, pricing strategies are one of many ways to increase sales. That pricing items slightly below the next whole dollar works is supported by numerous studies. The most commonly proposed explanation is that consumers read from the left and tend to drop off or pay less attention to the rightmost digits.

Researchers from Union College and Rutgers University provided direct evidence for this explanation in a 2005 study. In different trials, the researchers had 122 test participants estimate how many items of different prices could be purchased for $73. The participants thought they could buy significantly more items priced with 99-cent endings than items with comparable 00 ending prices.

Analysis of estimation errors indicated that the participants treated a substantial proportion of items with 99-cent ending as if their costs were up to a dollar less than they actually were, thus reflecting a pattern consistent with the drop-off explanation. As expected, increased motivation to come up with better estimates moderated the effect.

Despite my focus on two-digit endings, prices with a single 9 ending are common and highly effective as was shown, for example, in a 2003 study by researchers from the University of Chicago and MIT. In one of their three field experiments to test the 9 ending, they priced a women’s clothing item at $34, $39 and $44. The item sold best at $39.

Wrap Up
Psychological pricing has been inescapable for so many years, why should it bother me? Mostly, I suppose, because I feel the vendor is treating me like a fool. I do that well enough on my own, without the help of the price of salami ($5.99/lb).

Part of a supermarket
circular, April 2017.
The attempt to drive sales is so obvious, it’s just a distraction. If I’m comparing prices, I’ve always rounded the price to the next whole number, though in a supermarket, I can now rely on unit pricing.

Anyway, as my pet peeves go, this one isn’t as bad as people saying no problem instead of you’re welcome, which I addressed in an earlier post, Linguistic Longings. But I do wish we could make it go away. I’d ask you to join me in a boycott, except there would be nowhere to shop. Oh well, thanks for stopping by.

Example reading on psychological pricing:
Union College and Rutgers University study in Psychology and Marketing journal: onlinelibrary.wiley.com/doi/10.1002/mar.20084/abstract
University of Chicago and MIT study in Quantitative Marketing and Economics journal: link.springer.com/article/10.1023%2FA%3A1023581927405

05 May 2017

Medical Second Opinions

Welcome back. I’ve been lucky. Over the years, I’ve had only one medical issue whose solution was uncertain enough to seek a second opinion. According to the National Academies’ 2015 report, Improving Diagnosis in Health Care, diagnostic errors--inaccurate or delayed diagnoses--persist throughout all settings of care and continue to harm an unacceptable number of patients. It is likely that most people will experience at least one diagnostic error in their lifetime, sometimes with devastating consequences.

Getting a second opinion
(multiple websites)
That report identifies four types of information collection in the diagnostic process: obtaining the clinical history and interview, a physical exam, diagnostic testing and sending a patient for referrals or consultations. Regarding the last, while patients can obtain a second opinion on their own, as I did, clinicians may refer to or consult with other clinicians for additional expertise to help confirm or reject their working diagnosis or provide information on treatment options.

Second opinions didn’t come to the forefront for me because I or a family member or acquaintance have an ambiguous, uncertain or undiagnosed medical problem. It’s only because I came upon a recent study that provided some rather eye-popping metrics on the value of second opinions. I thought you might be interested.

Diagnostic Agreement With Referrals
To get a measure of how frequently final diagnoses vary and change the direction of medical care, researchers from the Mayo Clinic conducted a retrospective analysis of the records of 286 patients. The patients had been referred to the clinic by physicians, physician assistants and nurse practitioners from primary care practices in the years 2009 and 2010.

Comparing the referral diagnoses with the clinic’s final diagnoses, the researchers found the diagnoses agreed in only 12% of the cases. The final diagnoses were distinctly different than the referral diagnoses in 21% of the cases, and the final diagnoses were better defined or refined in 66% of the cases. There were no real differences associated with the types of provider making the referral.

Wrap Up
Because health care cannot be separated from cost, the researchers tallied the costs for the second opinion, including the referral visit and services within the first 30 days. As would be expected, the total costs for cases when the final and referral diagnoses differ were significantly higher than the costs for cases of either the confirmed or refined diagnoses.

The study findings emphasize the importance of the National Academies’ effort to improve medical diagnoses. Getting it right without delay can be a matter of living or dying. Correct diagnoses become all the more important when referrals may be limited by insurance.

Fortunately, Congress is on top of the problem and we’ll soon be able to relax. I’ve heard it’s gonna’ be great. Thanks for stopping by.

National Academies report: www.nap.edu/catalog/21794/improving-diagnosis-in-health-care
Mayo Clinic study in Journal of Evaluation in Clinical Practice: onlinelibrary.wiley.com/doi/10.1111/jep.12747/full
Article on Mayo Clinic study on ScienceDaily website: www.sciencedaily.com/releases/2017/04/170404084442.htm