The focus on kg/m2 (BMI) I cannot understand. Surely the lowly “body fat percentage” should be a better variable than kg/m2? Bodies are three dimensional you know!
It's a perfect tool to use for studies like these, as it can contribute understanding society-level concerns about the obesity epidemic and what impact we can expect it to have if it continues not to be tackled.
But like with almost all medical and nutritional research, drawing conclusions for yourself as an individual based on these population-scale studies is inevitably fraught. In the case of BMI studies, you can often get a fair sense of whether you should be concerned or not, but do need to take into account other things that you know about your lifestyle and health. Your doctor, presumably, does exactly that.
Meanwhile, body fat percentage tends to be very hard to measure accurately in the first place and has different techniques that tend to have different error characteristics, making it hard to correlate it between studies done through different clinics, let alone against someone's personal assessment at home or with their personal doctor/trainer/whatever. It probably has high relevance to some medical and nutritional outcomes, but isn't a very useful input variable for research because its inescapably noisy.
Perhaps my low IQ is showing, but why is one metric heavily criticized while the other is not? (Rhetorical)
It's in the same category as all that "alpha male" theory, Meyers Briggs, polygraphs, and "left vs right brained" people.
I'm starting to see more awareness around the concerns of "ballistic forensics" too, which is heartening.
Devil's Advocate: Then why is it so heavily used still? (Then again, I guess back to my initial point -- the same could be said for BMI.)
I went through the arduous process merely for the formal documentation, which in hindsight has served me well. Not a single doctor has ever questioned my diagnosis. However, as the psych told me, a 10 minute conversation with me should honestly have been evidence enough. ;)
I think this is the part you're getting wrong, which is why you're confused.
IQ was contentious from its introduction in the beginning of the 20th century, caught some traction in the mid-century, and has mostly been on a decline of esteem and respect again since. It's never been very broadly accepted, let alone spared from criticism, nor have most other psychometrics, although (as always) there are bubbles of academia, industry, and the general population that swear by them and work to legitimize them.
Kurt Danziger has published really great histories of all this.
I'll add that his books are especially interesting in the context of all the AI buzz as insight into the history of "intelligence" (the word, the socially constructed concept, etc) helps wrap one's head around what it means when people working in CS try to repurpose its terminology in their own field.
Also, by populations, do you mean groups of particular types of people or just groups of people in general? If anything, I thought IQ really only had anything close to merit at large population levels. Much of what I have read clearly fails at an individual level.
However, if you are talking about IQ's application in regards to populations like one race vs. another, then yes, I think the pushback is well deserved.
Inside certain bubbles, sure, because there's pressing demand to have something quantifiable and sufficient supporters willing to assert its legitimacy.
But good luck taking your test results outside of those bubbles to earn you some opportunity or respect, even if you can say your test was administered to the highest standards by the most respected administrators.
Nobody here will take your results to mean anything. Nobody at your work will take your results to mean anything. The recruiter at some new potential job won't either. The prestigious university you want to attend won't care. Most of your partners and friends probably won't.
Many of them may already have a sense of whether you're "intelligent" or not, either from personal interactions or from other practical indications. But good luck finding somebody of material influence who would hear your IQ score results and change their mind. It just doesn't have that weight.
That's what it means for it not to be treated seriously outside of bubbles. There are supporters that back it, and there are institutions that rely on it, but outside of those very specific places, there's very very little trust in it.
You'd think someone tried to convince those in the bubble that the Earth is flat. In my experiences, I have been met with all kinds of rebuttals like, "The test he took was probably over-weighted in verbal vs. spatial reasoning" or "He probably just blew the whole test off."
No one has a copy of the actual results to my knowledge, but he and his sister (who oddly enough scored higher) verified the story back in the day according to biographers. So, not telling what is the true story.
For the sake of argument, let's assume Feynman's score was indeed accurate. I think it makes people extremely uncomfortable for two reasons:
1. Some individuals with high IQs (IQ >= 130) feel threatened or ashamed by the fact that someone with an high but unremarkable score was capable of truly remarkable contributions to their field.
2. The scores are truly not always accurate or might potentially measure something that isn't intelligence.
If Feynman's score was indeed an inaccurate measurement of his intelligence, then that says more than I need to know about IQ testing.
I mention Feynman because I am in agreement with you:
> Many of them may already have a sense of whether you're "intelligent" or not, either from personal interactions or from other practical indications.
No one would consider Feynman to be unintelligent by any stretch of the imagination. However, at the end of the day, his score truly doesn't matter. Feynman nor anyone else is not remembered because of their intelligence, but rather, his contributions. Besides, exceptional people tend to be, well, exceptional.
not at a scientific level, no
Also wait until people find out the correlation between IQ and obesity (runs for cover)...
Perhaps you a right, because this is my main exposure to psychometric. From much of what I have read from various journals, there are clearly those that are contrarians, but mainstream academic psychology presents IQ as if IQ is some infallible measurement of human intelligence.
Despite IQ's merits being contentious (like BMI), it is still widely used regardless. IQ testing is still used for clinical diagnostic purposes (why I had to take one), entrance in to some gifted academic programs, in judicial contexts, etc..
Based on my personal research and experiences, I align with the contrarian views vs. the mainstream, academic views.
I think the concept is bullshit myself, but regardless the damage is done, and still being done for what it is worth.
I'm seeing the tide turn (imo), but by no means am I claiming it's no longer used (regardless of merit). I acknowledge I'm starting a personal anecdote which is subject to my own biases such as cohort affects.
Which seems odd, because I've yet to see anyone who doesn't believe that stupidity exists and it's the other side of the same coin.
I do not think that is the argument though. Clearly, there is some sort of distribution of all human attributes. I think the argument is in how (in)accurately something as qualitative and arbitrary as intelligence can be measured.
I like the analogy of athleticism. Some people are more athletic than others, but again, such differences are generally highly contextual. I am sure some sort of test composed of factors like the number of push-ups, sit-ups, and time trial of a 100m dash could be used to generate some sort of AQ (athletic quotient).
However, scoring high on the 100m dash might positively correlate with performance in sports, but I would not wager that a high AQ is truly indicative of athletic performance as a whole. At least not in any transitive sense when mapped to many sports. For example, Usain Bolt might have a very high AQ because of his running ability, but his AQ might not serve him well in a game of ice hockey or swimming.
Or when they saw that knowledge of arcane sport rules interfered, they could look for a more pure test of ability rather than knowledge, which they did with IQ by going from tests of specific factual knowledge to Raven's progressive matrices.
And when you do that kind of work, you find that you can develop better measures that have a lot of predictive power for whole populations, even if they do not tell you, say, how many goals they'll score in their next hockey game.
That does not make BMI a good measure.
I'm an outlier myself, and so is anyone who did some serious sports for a significant amount of time. There are other reasons to be an outlier too. But they're not so statistically significant.
That is doubtful, but possible
It is used for individuals. That is where it is harmful
It's hard to conceive of anyone meaningfully "harmed" by being a BMI outlier.
The only real occassion it comes up is when some lean and uncommonly athletic person gets miscategorized as obese and get warned of increased risks to their wellness if they don't lose weight. A warning which they generally laugh at because they know their own situation.
That's hardly "harm" -- "mild social nuisance" is more apt.
"You are fat. You must diet."...."Oh my Dog!! I am fat!!! I will fast"
Imagine a 180cm 98kg male. That would be a BMI of 30. How often do you see people of that size with visible abs? And of those, how many are the ones who've never touched steroids, sarms, peptides and hgh?
If a person's BMI is less than 30, they are going to be okay no matter what their body composition, and with a BMI of 30+ they aren't going to be okay, whether they are fat or jacked. Both obese and insanely built people put massive strain on their knees and back, both typically have high blood pressure.
Then the adipose tissue itself has various negative inflammatory effects on health, which sceletal muscle doesn't, and fat people encounter psychological side-effects of being unattractive, which jacked people don't, but PED use has its own list of well-known issues, and being THAT MUCH into bodybuilding is highly correlated with body dysmorphia alongside other physch issues.
So both are bad, and when speaking about general population health, we shouldn't really focus on body composition- BMI is good enough marker on its own
The rest of my life also revolved around recovery and nutrition because very quickly I realized that I needed to make extraordinary efforts to allow my body to recover from the regimen. I slept 10+ hours and ate around 3300 cals daily (TDEE was massive).
Being on antidepressants at the time made eating these amounts much easier, as it seemed to turn off something in my brain responsible for me feeling satiated.
I started gym after being diagnosed with the psych issues. I really put 110% effort into it and got… big stretch marks because my muscles grew so fast. I don’t think what I was doing was ”healthy” as much as it was ”I am super depressed and heavy barbell squats is my coping mechanism”.
I just wanted to say, you don’t need PEDs to get ”scary” jacked. But you probably need to be crazy like me.
Still, to break that bmi 30 barrier significantly, while maintaining the same level of leanness, you'd likely require some additional 'help'.
And again - it is possible for a number of gifted people, just highly unlikely. Most males can't get that jacked no matter how much and how hard they train. I'd say that even with PEDs most wouldn't break that barrier while staying lean.
My personal best was a 28 bmi with what looked like a 9% body fat, veins fully visible at the lower abs and the hips etc, and it was absolutely unsustainable for more than a year, for a plethora of reasons. Can't even imagine gaining 3 more points.
To reiterate: I'd still focus on a BMI to gauge the public health - the genetic outliers are rare
The suggestion of using BMI + waist circumference is an easier to measure risk factor than bodyfat percentage and helps to better capture those outliers.
Do you have evidence for this? (Assuming getting jacked without the use of steroids)
https://peterattiamd.com/belindabeck/
The medical problems with excess muscle mass tend to be more on the cardiovascular system than the skeleton. And the process of gaining a lot of muscle mass can increase the risk of musculoskeletal injuries (especially if using PEDS), which is a key confounding factor when looking at population health statistics.
What is so hard to accept that BMI is a good measurement?
Imbecile.
kg/m2 is akin to height and width which is 3 dimensional