Loading ...
Sorry, an error occurred while loading the content.

1874[evol-psych] Re: Iq" genetic or environmental?

Expand Messages
  • Irwin Silverman
    Dec 3, 1999
    • 0 Attachment
      On Fri, 3 Dec 1999, Peter Kabai wrote:

      > So when discussing what heritability really means,
      > besides being critical about the methods of measuring the trait, one also
      > should keep in mind, that the estimate is restricted to the population in
      > which it was measured.

      Stated more precisely, the estimate is restricted by the variance
      in evironmental conditions affecting the trait inasmuch as genetic
      variance between relatives may be assumed to be constant across populations.
      Thus, heritabilities are generally reported in terms of a range of estimates.
      For example, studies carried out in London, Ontario have found
      heritabilities based on co-twin studies in the area of .70 for various
      personality traits while the Minnesota studies, based on a much broader
      geographical base and hence a wider scope of environments, find estimates
      of about .50 for similar traits. It is an intrinsic limitation of the
      method but no biggie relative to the intrinsic limitations of most other
      behavior science methods - that is, if it is understood and applied
      appropriately.

      > Heritability of the eye colour is zero in a population of individuals all
      > having brown eyes

      This seems pointless - If eyes were all one color then there
      wouldn't be variance to measure and it would not be a variable.
    • Show all 20 messages in this topic