#selectionbias

[yumearcana]

Salon Hypnosis and the Myth of the "Thin Woman"🌀

Gentle notice: this writing has a calming and hilarious rhythm. Follow only if you feel safe doing so. ✦ ᛉ ᚨ ᚷ ᛟ ✦

Have you ever noticed it? On the hypnosis stage, amidst the crowd, a certain type of volunteer always seems to get chosen. The spotlight, again and again, finds the same profile: often female, almost always slender.

Is it bias? A silent prejudice playing out under the lights? Yes. And no. The reasons are far more practical, and far more brutal.

Reason One: Safety. The Sacred Duty of the Catch.

Let's be blunt. Have you ever tried to catch dead weight? I don't mean a stumble. I mean the complete, sudden, and total surrender of muscular control that can happen in a deep trance. It’s a sack of potatoes with a human soul.

If a subject drops and there's no one to catch them, that's not a failed bit. It's a concussion. A lawsuit. The end of the show. Forever. It is the hypnotist's sacred, non-negotiable duty to control that fall—every angle, every impact.

So, a word to my fellow practitioners: in addition to polishing your inductions… train your biceps. A strong frame isn't a vanity; it's a professional requirement. Otherwise, you'll have a subject with a head injury and a trance that's very, very bad for business.

Reason Two: The Physics of the Performance.

A lighter person is simply easier to maneuver. The entire spectacle relies on visual comedy and physical gags—the "human plank," the "sleeping beauty," the guided stumble. Positioning a volunteer for these routines needs to be smooth, swift, and safe. It's not about strength alone; it's about control. Guiding a slender frame to the floor is a ballet. Catching a heavier one is a construction accident waiting to happen.

Reason Three: The Unspoken Filter of Personality.

Let's be honest. The stage doesn't want a wallflower. It wants a performer. And certain personality types—the extroverted, the attention-seeking, the unashamedly dramatic—may, for a complex soup of social and cultural reasons, be more common in people of a certain physique. Is this a hard scientific fact? No. Hypnosis is an art, not a science, and these things aren't studied in a lab.

The hypnotist, with a performer's intuition, is scanning the crowd. They're not just looking for a glazed-over stare; they're looking for a spark. They select those who seem "on," who seem ready to play, who radiate that "look at me" energy. And yes, often, those people are women. We tend to be… more expressive.

So, if you're thinking of volunteering, ask yourself the right question. Look at the hypnotist. Look at their assistants. Ask yourself: is this safe? For them? For you?

And for the love of all that is holy, let's all do our part to avoid calling the doctor. The show, after all, must go on.

✦ᛉumeᛋᛇ✦

[eui-memes]

#selectionbias https://www.instagram.com/p/CPnB2qpl_9U/?utm_medium=tumblr

[stag28]

"The poorest men in the U.S. have life expectancies comparable to men in Sudan and Pakistan; the richest men in the U.S. live longer than the average man in any country. [..] The study found that life expectancy generally correlated negatively with rates of smoking, obesity, and lack of exercise, “suggesting that any theory for differences in life expectancy across areas must explain differences in health behaviors.” On the other hand, factors such as access to health care, residential segregation, and unemployment weren’t strongly related with life expectancy per Chetty’s research. [..] The areas where poor Americans tended to live the longest were those with high average incomes, high levels of education, and high government expenditure. A number of potential reasons could explain these positive correlations. Some of these cities may have policies that discourage smoking and sugary drinks and encourage exercise, for example. They may also have more public health services that low-income residents can take advantage of. On the other hand, poor populations in these places might differ from those in other cities: New York, for example, is home to more immigrants, who tend to live longer than native-born Americans."

[belranto]

Alpha Selection Bias

Every weekday morning Seeking Alpha, the widely followed investing website, sends out an email, “Wall Street Breakfast: Must Know News.”  It’s not news, but it is a good, if idiosyncratic, round up of market-related events, and I read it almost every day.  (You can get this by creating a free account and selecting it from the "Alerts" tab.)  

Wall Street Breakfast also contains a section called “Alpha-Rich Stock Movers and Great Calls” which is a first rate example of hindsight bias, data mining, sample selection bias, and perhaps herding as well. 

Each day this section identifies 2 or 3 successful stock calls made by contributors some time in the recent past.   Implicit (or maybe not so implicit) is the assertion that these successes are the result of alpha uncovered by the authors.

What Seeking Alpha is doing is cherry-picking the winners with hindsight and showing them off as prescient, alpha-rich analysis.

Seeking Alpha doesn’t report on the aggregate performance of all the stock calls that they had identified as ‘alpha-rich’ when they were made.  There is no model portfolio containing all the stock calls. 

No systematic consideration is given to the contemporaneous performance of peers and the broad market.

I think (I can’t tell for sure) no consideration is given for serendipitous events unrelated to the original stock call. 

No account is taken of the possible impact of the initial call itself on investors’ short-term price assessments (e.g., some stock sites list as news the date on which a stock is highlighted by Seeking Alpha). 

It is fun to read stories about great calls, and to give kudos to the people who made those calls.  But it isn’t possible to infer anything about their alpha-richness based on the information Seeking Alpha shares with its readers in its daily email.