PSY 101 Lecture Notes - Lecture 4: Distant Relatives, Twin, Heritability
Document Summary
Dominant genes: if you inherit a dominant gene for a trait from one parents then that trait will be expressed. Recessive genes: recessive genes for a trait are only expressed if you inherit two of them (one from each parent) Polygenetic traits: traits that are controlled by multiple genes and often are affected by environmental and social factors (i. e. height, freckles, intelligence) Heritability: a statistical formula that provides a percentage of variation in a population attributable to genetic factors rather than to differences in the environment. Family studies: if a specific trait is inherited, biological relatives should show increased trait similarity, compared to unrelated people closer relatives, like siblings, should show more similarity than distant relatives. Genetic traits are not fixed/inflexible: lifestyle and environmental factors can influence whether genes become expressed. Heritability estimates apply to groups, not individuals: estimates (e. g. , a particular trait is. 50% heritable) only apply to populations, not individuals.
