Intelligence of the Mother, Temperament and Physical of the Father - although this concerns humans, I've found that this is pretty much true of dog breeding also. Not an absolute in dogs as if we are using dog's with a high COI (inbreeding coefficients) brains and or beauty can be skewed by the preponderance of fewer ancestors.

Do Children receive their Intelligence from their Mothers?

In an essay in the weekly Lancet medical journal, an Australian geneticist has recently suggested that relatives and friends may be getting things backward when they wish a baby the good looks of its mother and the brains of its father.  Or, restated in another way, smart men may be bright because of genes they inherit from their mothers.  Gillian Turner (1996) of Hunter Genetics in Newcastle, New South Wales says that a growing body of evidence suggests that several genes, actually "eight discrete localizations", which determine intelligence appear to be located on the X chromosome, the chromosome that men inherit from their mothers.  Such localizations or genes "extend over the short and long arm of
the X chromosome" (p. 1814).

For the purposes of her most informative essay, Turner defined intelligence  "as the ability to deal adaptively with the changing environment, to benefit from past experiences, to proceed in goal-directed fashion, to pursue productive avenues of problem solving, and to perceive common properties in otherwise separate domains of experience" (p. 1814).  

In Turner's own words, "these genes are distributed along the whole length of the X chromosome and, presumably, code for various anatomical or functional parts of the neural substratum of intelligence" (p. 1814).  That is, women carry the gene for intelligence on their X chromosome and are solely responsible for passing it on to their sons.

Thus, Turner forewarns men that they should temper hormones with logic when selecting the mothers of their children and go for brains rather than for good looks.  Similarly, she feels that women are more able to select their partners for their looks as they could be assured that brains comes from the female side.  

To repeat once again, Turner's argument goes along these lines.  Because the genes for intelligence are on the X chromosome, a single mutation will have more effect on a man than on a woman.  This is because a woman inherits two X-chromosomes, one from her father and one from her mother.  Therefore, if she inherits a mutant gene on the X chromosome from one parent, there is a good  chance that she will inherit a normal gene on the X chromosome from the other  parent which will dilute the mutant's impact (see Cooper, 1996; but for a  critical analysis, see Scully, 1996).  

However, a male has only one X chromosome, inherited from his mother.  It is  paired with the much smaller Y chromosome from his father.  And because the Y chromosome is so small, it does not have a gene to match every gene found on the X chromosome.

As a result, in a male, a mutant gene on the X chromosome is likely to be the only such gene and, unopposed, will have its full effect.  Conversely, if the predominate gene is not as strong as it should be, the man is more likely to suffer mental retardation.  Turner's current hypothesis that if the gene is the one that increases intelligence, then its full effect will be seen in men, while in women the benefit is less pronounced.

This explains, she states, why some men are extraordinarily intelligent.  She concludes her two-page article by suggesting to men that if they want smart sons their best bet is to marry a smart woman.  

To summarize, this discovery that women pass on their intelligence gene to male offspring via the X chromosome is significant for mate selection.   Hence, a woman can choose a brawny mate yet still be assured of bearing intelligent children since she has an extra X chromosome.  Meanwhile a man's "primitive urges in mate selection are coded in his genome, and that they  target current ideals of sexual attractiveness and youth" (Turner, 1996, p. 1815).

So if a man wants to have smart sons, Turner concludes, his best chance is to marry a smart woman, for it appears it is her X chromosome genes that will determine how bright her boys will be.  

Cooper, Glenda, (1996, June 28).  Brainy sons owe intelligence to their
mothers. Independent, p. 4.  
Scully, Jackie Leach   (1996, July 02). Genes don't make us what we are.
Independent, p. 11.  
Turner, Gillian  (1996, June 29).  Intelligence and the X chromosome.  The
Lancet, 347(9018), 1814-1815.

Click here to read an additional article on the inheritance of temperament in cats.