Do you consider intelligence to have a stronger genetic or environmental basis?

Since the term nature-nurture was first initiated by Galton (1883, c.f. Plomin, 1988) the question of whether intelligence has a stronger environmental or genetic basis has been the source of much controversy and debate (Bouchard., Lykken., McGue., Segal., & Tallegen, 1990a, 1991., Bouchard & McGue, 1981., Hernstein & Murray, 1994., Plomin, 1988., Scarr 1997).

Traditionally, research into intelligence has been separated by two opposing positions; Behavioural Genetic Theory and Socialization Theory (Scarr, 1997). Whilst Socialization theory provides useful insights into the qualitative nature of differences in behaviour and intelligence, methods used by such research are criticised as being…(short extract)