JOHN RISELEY makes an odd assumption regarding sperm donors (HAS, May 7), namely that intelligent people have intelligent off-spring, and hence unintelligent beings bear less intelligent children. This implies in any given family all siblings would have the same IQ or measured ability.

My parents’ 14 siblings had a wide spectrum along the intelligence quotient scale.

Equally my brother and I differ greatly: while I have a higher mathematically and literal score, his visual-spatial result is far in excess of mine. This is despite us being brought up in the same environment.

The biggest barrier to Mr Riseley’s rather unhealthy desire for the so-called successful child is nurture. More often than not, the degree of nurture and development is directly related to financial resources, which in turn relates to access to better education and childhood experiences.

Putting a child conceived from “intelligent sperm” into a lowincome family could also deny the developing child the necessary vitamins and healthy diet connected with educational success, particularly in early schooling. In any event, the letter implies that “intelligent people” make better people – an idea which is wrong.

B Jackson, Sacriston.