What I Learned Today

I was raking up a ton of leaves that had fallen in my yard when I discovered a little ball of brown and black amongst the leaves. I repositioned him in a tree and took a picture:

I did some sleuthing and found that this is a wooly bear caterpillar (they roll into a ball when disturbed). They transform into the beautiful Isabella tiger moth.

I marvel anew at how different these forms can be. And then there’s this amazing part of its lifecycle:

The banded woolly bear larva emerges from the egg in the fall and overwinters in its caterpillar form, when it literally freezes solid. First its heart stops beating, then its gut freezes, then its blood, followed by the rest of the body. It survives being frozen by producing a cryoprotectant in its tissues. In the spring it thaws. (Wikipedia)

Wow! I’ll have to look for this guy again in the spring. I hope he makes it :) (But maybe he’ll be a moth by then!)

I recently discovered iNaturalist, which is a website and smartphone app that encourages you to collect observations of plants, animals, and insects. By recording when and where they were observed, you contribute to the store of data about these organisms. This place must be every biologist’s dream come true! Data for free!

They’ve put some thought into how to ensure high quality data. When you log an observation of, say, a ladybug, you can simply record it as “insect” and let others refine it, or be as specific as you feel confident to narrow down its precise species. The crowd of other users will review your tag and vote for it as correct or make corrections. When an organism is pinned down at the species level, that observation becomes “research grade.”

So far I have contributed observations of a praying mantis (needs review) and a raccoon (research grade!). When you log an observation and connect it with a species, you also get to see a map of where else that species has been seen.

You can also “subscribe” to get updates whenever a particular organism of interest is spotted! I signed up for praying mantises (mantis religiosa), spiny lizards (at the genus level (sceloporus), not a species), and collared lizards (family crotaphytidae – a beautiful creature from my childhood). Just today I’ve seen a bunch of new lizard observations (one dead). I’m looking forward to more. (I’m also being exposed to the Latin names for things. What fun!)

Another cool feature is that you can browse an area (say, where you are currently standing) to see what has been observed there.` You can also join specific research “projects” and contribute your matching observations (e.g., a project might specify that they want only pictures of reptiles observed in southern California).

I love to see well constructed efforts to engage people in the process of science. This one seems particularly compelling and enjoyable to use.

I recently learned that there is a *maximum* age at which one can start training to be an air traffic controller. While a minimum age for various efforts is common, specifying a maximum age seemed curious, and especially given that the oldest you can be to start ATC training is 30 years old. So young!

Naturally, I wondered why this limit had been chosen. After some digging, I discovered that it derives from studies done in the 1960s and 1970s such as

• “Problems in Air Traffic Management: III. Implications of Age for Training and Job Performance of Air Traffic Controllers” by Trites and Cobb (1962)
• “The Relationship Between Chronological Age and Aptitude Test Measures of Advanced-Level Air Traffic Control Trainees” by Cobb, Lay, and Bourdet (1971)

Trites and Cobb (1962) conducted a study of ATC trainees and their subsequent job performance (in the first year of work) that showed a marked increase in training failure rates with age, up to age 45:

They do not speculate about reasons for the reduction in performance, concluding that

“Whatever the nature of the casual factors associated with chronological age and underlying the relationships of this study, there is no doubt that the number of potential training failures can be reduced and undesirable controllers eliminated by specifying a maximum age for entry into air traffic controller training. In the best interests of air safety and financial economy, establishment of an upper age limit is recommended.”

The FAA must not have heeded this advice, because nine years later, Cobb was still working to persuade them of the dangers of older ATC trainees. The Cobb et al. (1971) study is of 710 air traffic controllers, aged 21-52, that concluded that “age correlated negatively with 21 of the 22 aptitude measures and with training course grades.” This is a study of a biased sample, however: “because of their highly specialized pre-employment experience, these men were not required to qualify on the CSC ATC Aptitude Screening Test.” It is perhaps unsurprising that they might have lower aptitude measures, since these were not used to screen them as applicants. However, the negative correlation of performance with age is there. In Figure 2 from this paper, black means “failed basic training course”, hashed means “course grades comprising the approximate lower half of pass group”, and white means “course grades comprising the approximate upper half of pass group”:

The numbers in the right column are the number of subjects in each age group. “Although the subjects over age 34 represented only about 23 per cent of the 710 men involved in the entire study, their failure rate (31.1 per cent) in Academy ATC training was about three times that of the younger trainees.”

Cobb et al. went on to test these subjects on a variety of mental tasks, including simple arithmetic, spatial reasoning, following oral directions, abstract/logical reasoning, and a job-relevant task described as follows: “A highly-speeded test consisting of two parts of thirty items each. In each part, the subject is presented a flight data display for several aircraft and must determine whether certain changes in altitude may be directed without violating a specified time-separation rule.”

Performance on every single test, except arithmetic, was negatively correlated with age.

Maybe this result, or others like it, did the trick. The right of the FAA to establish a maximum age for its air traffic controllers was passed into US Law in 1972. The current version of the law states that

“The Secretary may, with the concurrence of such agent as the President may designate, determine and fix the maximum limit of age within which an original appointment to a position as an air traffic controller may be made.”

Today I came across a mention of an interesting study, titled:

Female Partners of Men Who Use Pornography: Are Honesty and Mutual Use Associated With Relationship Satisfaction?

Annoyingly, only the abstract is available; the article costs $39. But from the abstract, we have:

“Participants reporting more honesty showed higher satisfaction and lower levels of distress, and participants disclosing mutual use showed lower levels of distress, although no differences were reported in satisfaction.”

… from which Scientific American concluded that being honest about your porn use leads to more relationship success. But it seems the study only interviewed heterosexual women about their male partners’ use of pornography. A bunch of questions crowded into my brain, like:

• What if more honesty about anything leads to more relationship success (because you feel there’s more communication or whatever)? Where’s the corresponding study on honesty about something that isn’t porn?
• Why is there an assumption that only men use porn, or that only women would be distressed by their partner’s use of it? Where’s the corresponding study on men’s opinion of their female partners viewing porn?
• Why the restriction to heterosexual women? Clearly they really wanted to focus on male use of porn. Or there’s some assumption here that it’s a male-only thing. I don’t think that’s true?

So then I browsed around and found this article (of course we only get the abstract again):

Pornography Use: Who Uses It and How It Is Associated with Couple Outcomes

which looks at porn use by both men and women. However, it concludes that “overall results from this study indicated substantial gender differences in terms of use profiles” (I’d be interested to know what they were) and that:

“Specifically, male pornography use was negatively associated with both male and female sexual quality, whereas female pornography use was positively associated with female sexual quality.”

Here I think “sexual quality” means something like “sexual satisfaction.” Or does it mean the quality of the sex one has? It’s also not clear whether “associated” means “what these couples report thinking about it” or “what we actually measured in these couples,” and I’m curious about what the negative associations were. And if any of that $39 were to go to the authors of the paper, I’d be tempted to pay it and find out.

Instead, I was able to find someone else’s summary of this article, which clarifies:

“Specifically, the men in the study were more likely to view pornography alone than the women, and this led to lower levels of sexual desire and lower levels of sexual satisfaction for both the men and the women.

By contrast, the women in the study tended to only view pornography when they were sexually aroused, and do so in the company of their partners. This increased the sexual satisfaction of both the men and the women.”

This suggests that porn viewing as a couple activity can be beneficial. Is there room in our society’s generally negative, condemnatory, and narrow view of pornography to accommodate these findings?

Three plastic surgeons decided to conduct a study of finger dexterity in violin and viola players versus the general population. The paper describing their findings, which was published in The Journal of Hand Surgery, has a title that tickles my funny bone:

Assessment of the presence of independent flexor digitorum superficialis function in the small fingers of professional string players: Is this an example of natural selection?, by Godwin, Wheble, and Feig.

The paper is, lamentably, behind a paywall, and I am unconvinced by the abstract that it is worth $32.00. But never fear, The Atlantic Monthly has provided a summary and analysis of the paper in an article titled Study: Violinists’ Fates Resides in Their Left Pinky Fingers.

The gist of their argument is that you can conduct tests to determine how much independent motion a person has for their pinky and their ring finger. Go ahead, test yourself:

Hold down the index, middle, and ring fingers of your left hand, then try to bend your pinky. Now try it again, but allow your ring finger to bend as well.

About 18 percent of people can do neither, according to a study in The Journal of Hand Surgery. But in a similar group of 90 professional musicians from “three of London’s leading orchestras” (38 first violinists, 33 second violinists, 19 viola players), none lacked this ability, and all but two were able to bend just their pinky finger.
(Source: Atlantic Monthly).

I can easily bend the ring and pinky fingers together, but I have only limited curl of the pinky on its own. Does this explain why I continue to struggle to get good intonation with 4th-finger stops?

Picture from http://www.the-violin.com/violin-fingering-E.html

Apparently, Godwin et al. recommend testing children for this ability prior to signing them up for violin lessons. As a filter? Really?

As a possibly-slightly-impaired player, I’m more in favor of the Atlantic’s take: “[Instead,] music teachers could use this knowledge to go easy on kids who aren’t predisposed to the violin, instead of just telling them to practice more.”