What David Gillies has expressed has been demonstrated in a number of studies involving adoption of very young children into extremely supportive homes with excellent environments. In the overwhelming number of cases, tested IQ tended toward close approximation to the mean of suggested by their inheritance.

Almost to no extent whatever. I don’t have the precise figure to hand, but the association is very weak. A good parental background might well have all sorts of salubrious effects in other areas, but as for how smart you are, barely a whit.

But I would also expect the committed parents to be more likely to see their offspring are well fed, well immunised, and less exposed to carcinogens, junk food, stuff like that. Wouldn’t you expect well nurtured children to grow into sturdier adults? Not only that, more mature and confident adults?

Maybe it comes down to nothing deeper than IQ being one, of many possible, signs of your biology being in good nick whereas early death correlates with your biology being in bad nick. Mind you, that won’t appeal to all those asses who attribute their success exclusively to their own moral virtue rather than, in part, the luck of the draw.

Yes

Research done on those born in 1958 shows the largest factor determining someone’s class destination is IQ accounting for half the explained variance in class variance . The amount of work is the next largest factor . The combined effects of class privilege or disadvantage are 17 % of the explained variance ( This from Professor Emeritus Peter Saunders but the research is well known.) If you look a the matter multi generationally the compounding of non class effects are overwhelmingly predominant .
The fact is then that a clever hard working boy despite Labour`s efforts to stop him , has a very good chance of changing his class . His children will suffer virtually no significant barrier if the characteristic are inherited .( Labour again wished to stop this movement by loading up inheritance tax and have not understood why it was so hated ).

…and No….

As a man who despite numerous advantages has achieved almost nothing I find this somewhat uncomfortable .Personally I massage my bruised ego by reminding myself that the possibilities of objectively measuring IQ between classes ,or indeed establishing what class background someone comes from, are small.
Is it really true that the people of Surrey are vastly cleverer than the people of Wales . I doubt it . Is it true that in parts of Glagow men are some 50% stupider than in the average golf club…

Doubt it Timmy , old fruit , doubt it .

I’d give more credence to higher intelligence being more likely to correlate with greater prospensity to deferred gratification.

You have to be really quite stupid not to know how “to pursue healthy behaviours”. The question is whether you can arsed.