1. The US military uses IQ testing to determine potential recruits' cognitive abilities?

No. The military does not take IQ tests. As already noted, the test to be taken is the ASVAB from which a subset called AFQT is often likened to 'something similar'. But AFQT is not an IQ test, is scaled differently and designed with different aims and validations.

Comparing them is not easy. They measure different things. Only the mathematical construction to express the numbers is the same: an assumed "normal distribution". Body height and idiocy are both normal distributed, and they have a correlation. Converting height to intelligence is still not plausible, even if the military should reject men below a height of 1.66m as being the tenth percentile on height scales for the US.

2. the military forbids anyone with an IQ under 83 from joining.

No. The military does not say anything like that.

If anyone entertains the false equivalent of AFQT=IQ-test then it still says nothing anywhere about "83" and nothing in that thought 'corresponds' to "83".

That the lowest 10th percentile of AFQT test takers cannot join is unrelated to IQ. But let's make up a thought experiment:

The lowest 10th percentile of IQ is described by the military itself as corresponding to an IQ of 72:

The 10th percentile IQ score for Cattell Culture Fair is 69.

So if AFQT were an IQ test,

or better thought of as:
"if the military would recruit people based on IQ testing and apply the same scaling and 10th percentile cut-off",
then the category IV would mean people with IQs of 69 or 72 or 81 would still be allowed to join on that IQ measure alone.

Another answer notes (which is also the source for the picture above)

This 37 year old military report suggests

but should be rewritten as

that Peterson's claim is incorrect.

Military doesn't do IQ testing, and test used if one assumes correspondence in scaling for cut-offs allows for IQs as low as 69.

3. because their experience has shown that anyone with an IQ under 83 will be more of a liability than an asset to the military?

As numbers 1 and 2 have already shown, it is meaningless to search for "83" in military documents, or regulations –– as Peterson made the whole story up or just confused everything else but "1 in ten" or what would or should follow from that. It is unclear what he wants to achieve with this misinformation disguised in numbers?

Perhaps Peterson believes the military uses a Peterson-IQ scale for determing a 10th percentile cut-off "at IQ 83"? Such a test would then be scaled to a standard deviation of 13.1962. A lucky number in front and the decimals being Petersons birth year? Then it would make some sense, although such a non-standard standard deviation would be a bit on the unique side?

Important update:

Downvotes convinced me otherwise. I recant. The above is untrue. Right is: Peterson is infallible. Everything he says is true and people should recognize that. The military uses a mysteriously unnamed IQ test to determine cognitive abilities. If anyone tests below exactly 83 in that test he will be forbidden to join the greatest club there is. Because of Peterson's infallibility the "internal tests"-thing must also be true.

1. The US military uses IQ testing to determine potential recruits' cognitive abilities?

No. The military does not take IQ tests. As already noted, the test to be taken is the ASVAB from which a subset called AFQT is often likened to 'something similar'. But AFQT is not an IQ test, is scaled differently and designed with different aims and validations.

Comparing them is not easy. They measure different things. Only the mathematical construction to express the numbers is the same: an assumed "normal distribution". Body height and idiocy are both normal distributed, and they have a correlation. Converting height to intelligence is still not plausible, even if the military should reject men below a height of 1.66m as being the tenth percentile on height scales for the US.

2. the military forbids anyone with an IQ under 83 from joining.

No. The military does not say anything like that.

If anyone entertains the false equivalent of AFQT=IQ-test then it still says nothing anywhere about "83" and nothing in that thought 'corresponds' to "83".

That the lowest 10th percentile of AFQT test takers cannot join is unrelated to IQ. But let's make up a thought experiment:

The lowest 10th percentile of IQ is described by the military itself as corresponding to an IQ of 72:

The 10th percentile IQ score for Cattell Culture Fair is 69.

So if AFQT were an IQ test,

or better thought of as:
"if the military would recruit people based on IQ testing and apply the same scaling and 10th percentile cut-off",
then the category IV would mean people with IQs of 69 or 72 or 81 would still be allowed to join on that IQ measure alone.

Another answer notes (which is also the source for the picture above)

This 37 year old military report suggests

but should be rewritten as

that Peterson's claim is incorrect.

Military doesn't do IQ testing, and test used if one assumes correspondence in scaling for cut-offs allows for IQs as low as 69.

3. because their experience has shown that anyone with an IQ under 83 will be more of a liability than an asset to the military?

As numbers 1 and 2 have already shown, it is meaningless to search for "83" in military documents, or regulations –– as Peterson made the whole story up or just confused everything else but "1 in ten" or what would or should follow from that. It is unclear what he wants to achieve with this misinformation disguised in numbers?

Perhaps Peterson believes the military uses a Peterson-IQ scale for determing a 10th percentile cut-off "at IQ 83"? Such a test would then be scaled to a standard deviation of 13.1962. A lucky number in front and the decimals being Petersons birth year? Then it would make some sense, although such a non-standard standard deviation would be a bit on the unique side?

1. The US military uses IQ testing to determine potential recruits' cognitive abilities?

No. The military does not take IQ tests. As already noted, the test to be taken is the ASVAB from which a subset called AFQT is often likened to 'something similar'.

2. the military forbids anyone with an IQ under 83 from joining.

No. The military does not say anything like that.

If anyone entertains the false equivalent of AFQT=IQ-test then it still says nothing anywhere about "83" and nothing in that thought 'corresponds' to "83".

That the lowest 10th percentile of AFQT test takers cannot join is unrelated to IQ. But let's make up a thought experiment:

The lowest 10th percentile of IQ is described by the military itself as corresponding to an IQ of 72:

The 10th percentile IQ score for Cattell Culture Fair is 69.

So if AFQT were an IQ test,

or better thought of as:
"if the military would recruit people based on IQ testing and apply the same scaling and 10th percentile cut-off",
then the category IV would mean people with IQs of 69 or 72 or 81 would still be allowed to join on that IQ measure alone.

Another answer notes (which is also the source for the picture above)

This 37 year old military report suggests

but should be rewritten as

that Peterson's claim is incorrect.

Military doesn't do IQ testing, and test used if one assumes correspondence in scaling for cut-offs allows for IQs as low as 69.

3. because their experience has shown that anyone with an IQ under 83 will be more of a liability than an asset to the military?

As numbers 1 and 2 have already shown, it is meaningless to search for "83" in military documents, or regulations –– as Peterson made the whole story up or just confused everything else but "1 in ten" or what would or should follow from that. It is unclear what he wants to achieve with this misinformation disguised in numbers?

Perhaps Peterson believes the military uses a Peterson-IQ scale for determing a 10th percentile cut-off "at IQ 83"? Such a test would then be scaled to a standard deviation of 13.1962. A lucky number in front and the decimals being Petersons birth year? Then it would make some sense, although such a non-standard standard deviation would be a bit on the unique side?

1. The US military uses IQ testing to determine potential recruits' cognitive abilities?

No. The military does not take IQ tests. As already noted, the test to be taken is the ASVAB from which a subset called AFQT is often likened to 'something similar'. But AFQT is not an IQ test, is scaled differently and designed with different aims and validations.

Comparing them is not easy. They measure different things. Only the mathematical construction to express the numbers is the same: an assumed "normal distribution". Body height and idiocy are both normal distributed, and they have a correlation. Converting height to intelligence is still not plausible, even if the military should reject men below a height of 1.66m as being the tenth percentile on height scales for the US.

2. the military forbids anyone with an IQ under 83 from joining.

No. The military does not say anything like that.

If anyone entertains the false equivalent of AFQT=IQ-test then it still says nothing anywhere about "83" and nothing in that thought 'corresponds' to "83".

That the lowest 10th percentile of AFQT test takers cannot join is unrelated to IQ. But let's make up a thought experiment:

The lowest 10th percentile of IQ is described by the military itself as corresponding to an IQ of 72:

The 10th percentile IQ score for Cattell Culture Fair is 69.

So if AFQT were an IQ test,

or better thought of as:
"if the military would recruit people based on IQ testing and apply the same scaling and 10th percentile cut-off",
then the category IV would mean people with IQs of 69 or 72 or 81 would still be allowed to join on that IQ measure alone.

Another answer notes (which is also the source for the picture above)

This 37 year old military report suggests

but should be rewritten as

that Peterson's claim is incorrect.

Military doesn't do IQ testing, and test used if one assumes correspondence in scaling for cut-offs allows for IQs as low as 69.

3. because their experience has shown that anyone with an IQ under 83 will be more of a liability than an asset to the military?

As numbers 1 and 2 have already shown, it is meaningless to search for "83" in military documents, or regulations –– as Peterson made the whole story up or just confused everything else but "1 in ten" or what would or should follow from that. It is unclear what he wants to achieve with this misinformation disguised in numbers?

Perhaps Peterson believes the military uses a Peterson-IQ scale for determing a 10th percentile cut-off "at IQ 83"? Such a test would then be scaled to a standard deviation of 13.1962. A lucky number in front and the decimals being Petersons birth year? Then it would make some sense, although such a non-standard standard deviation would be a bit on the unique side?

Important update:

Downvotes convinced me otherwise. I recant. The above is untrue. Right is: Peterson is infallible. Everything he says is true and people should recognize that. The military uses a mysteriously unnamed IQ test to determine cognitive abilities. If anyone tests below exactly 83 in that test he will be forbidden to join the greatest club there is. Because of Peterson's infallibility the "internal tests"-thing must also be true.

1. The US military uses IQ testing to determine potential recruits' cognitive abilities?

No. The military does not take IQ tests. As already noted, the test to be taken is the ASVAB from which a subset called AFQT is often likened to 'something similar'.

2. the military forbids anyone with an IQ under 83 from joining.

No. The military does not say anything like that.

If anyone entertains the false equivalent of AFQT=IQ-test then it still says nothing anywhere about "83" and nothing in that thought 'corresponds' to "83".

That the lowest 10th percentile of AFQT test takers cannot join is unrelated to IQ. But let's make up a thought experiment:

The lowest 10th percentile of IQ is described by the military itself as corresponding to an IQ of 72:

The 10th percentile IQ score for Cattell Culture Fair is 69.

So if AFQT were an IQ test,

or better thought of as:
"if the military would recruit people based on IQ testing and apply the same scaling and 10th percentile cut-off",
then the category IV would mean people with IQs of 69 or 72 or 81 would still be allowed to join on that IQ measure alone.

Another answer notes (which is also the source for the picture above)

This 37 year old military report suggests

but should be rewritten as

that Peterson's claim is incorrect.

Military doesn't do IQ testing, and test used if one assumes correspondence in scaling for cut-offs allows for IQs as low as 69.

3. because their experience has shown that anyone with an IQ under 83 will be more of a liability than an asset to the military?

As numbers 1 and 2 have already shown, it is meaningless to search for "83" in military documents, or regulations –– as Peterson made the whole story up or just confused everything else but "1 in ten" or what would or should follow from that. It is unclear what he wants to achieve with this misinformation disguised in numbers?

1. The US military uses IQ testing to determine potential recruits' cognitive abilities?

No. The military does not take IQ tests. As already noted, the test to be taken is the ASVAB from which a subset called AFQT is often likened to 'something similar'.

2. the military forbids anyone with an IQ under 83 from joining.

No. The military does not say anything like that.

If anyone entertains the false equivalent of AFQT=IQ-test then it still says nothing anywhere about "83" and nothing in that thought 'corresponds' to "83".

That the lowest 10th percentile of AFQT test takers cannot join is unrelated to IQ. But let's make up a thought experiment:

The lowest 10th percentile of IQ is described by the military itself as corresponding to an IQ of 72:

The 10th percentile IQ score for Cattell Culture Fair is 69.

So if AFQT were an IQ test,

or better thought of as:
"if the military would recruit people based on IQ testing and apply the same scaling and 10th percentile cut-off",
then the category IV would mean people with IQs of 69 or 72 or 81 would still be allowed to join on that IQ measure alone.

Another answer notes (which is also the source for the picture above)

This 37 year old military report suggests

but should be rewritten as

that Peterson's claim is incorrect.

Military doesn't do IQ testing, and test used if one assumes correspondence in scaling for cut-offs allows for IQs as low as 69.

3. because their experience has shown that anyone with an IQ under 83 will be more of a liability than an asset to the military?

As numbers 1 and 2 have already shown, it is meaningless to search for "83" in military documents, or regulations –– as Peterson made the whole story up or just confused everything else but "1 in ten" or what would or should follow from that. It is unclear what he wants to achieve with this misinformation disguised in numbers?

Perhaps Peterson believes the military uses a Peterson-IQ scale for determing a 10th percentile cut-off "at IQ 83"? Such a test would then be scaled to a standard deviation of 13.1962. A lucky number in front and the decimals being Petersons birth year? Then it would make some sense, although such a non-standard standard deviation would be a bit on the unique side?