Originally Posted by Grimalkin

Ah no, genotype is our personal collection of alleles, our own DNA, and phenotype is only the physical expression of this. There is quite a lot of genotypic variance among different populations of humans, although of course less then between a human and say a chimp or a turtle, its all relative. Some genes are dominant - you only need one allele to have "it", some can express "partial dominance" - like the intermediate mocha skin color of the child of an interracial couple, but many recessive alleles simply don't express at all if the individual is heterozygote - but it is there nevertheless in your genotype, but not your phenotype. Heritability is phenotypic variance measured through genotypic and environmental factors - so yes, families members tend to resemble one another because they share more traits in both ways.