BillD was on the right track in writing
"It is easy to begin. If Watson can refer to "...people who have to deal with black employees", I can refer to the black PHDs in math, physics, astronomy etc., who have shown that intelligence is not reserved to Watson's race ethnic group. (There IS only one 'race').

"If Watson thinks he can design tests that support claims like that, he should say so, or shut up"
but he could have gone further.

Watson belongs to the school of scientists that employs reductionism (limiting experimental design so that, in any experiment, all variables except one are kept constant and analysis is done on the effect of the one variable) and would probably accept Popper's dictum on defining science; a statement/hypothesis/idea is not scientific unless you dan design an experiment that could disprove it and, if your proposition can't be so tested it ain't science.

The plethora of examples already contradicting Watson's proposal categorises his statement as "poorly informed", at the very least. Watson'e abilities in experimental design may be excellent applied to DNA analysis but I've seen very little evidence that he is truly a polymath, let alone what used to be termed "a renaissance man." In the matters he addresses he's no better than Joe Bloggs, with due respect to any real people who revel in that name.

And when Bill writes
"There ARE some physical attributes that are associated with different groups, due to evolution...and yeah, 'most' white men CAN'T jump as high....and there are sound reasons why, just as sickle cell anemia is a disease of mostly black men"
he's displaying his US context.

There are at least three different alleles for sickle cell anaemia; each arose in separate areas where malaria was endemic, as a genetic response to the negative selection pressure applied on the human population. The one in the African American population did indeed come from west Africa but another came from the Mediterranean (particularly Italy and Greece, where I think people with black skins were originally a bit thin on the ground) and another comes from SE Asia and is also not associated with people who have black skins.

Cheers, Rowan