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)

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