Re: What does heritability mean in words that a lay person can understand.

Traits are "shown" or manifested in individuals in a population; not all 
individuals will manifest (or display) a given trait. This is due to the 
genes this individual inherits from its parents. Among individuals in a 
population that show a given trait there can be variability in the level of 
expression or degree of that trait. This variability in the degree to which 
a trait is observed in a population is due to the genes that control that 
trait and environmental influences. Heritability is an effort to measure 
the amount of variation due to genetics versus the amount of variation due 
to the environment.Thus, a statement such as "the heritability of this 
trait in a population is 48%" indicates that 48% of the variation of that 
trait observed in the population is due to different levels of gene 
expression. In others words, roughly half of the variation in the 
population wih regard to that trait results from genetic variation rather 
than environmental influences.