Low = very likely to behave in a particular way. About 50% of personality traits are genetically influenced. Non-shared = friends, teachers, etc. Behavioral genetic research methods personality - unique and relatively enduring set of behaviors, feelings, thoughts, and motives that characterize an individual. Relatively enduring; consistent trait - disposition to behave consistently in a particular way. Shared and unshared environment + error = nongenetic trait sources behavioral thresholds - point where one moves from not having particular response to having one. Quantitative trait loci (qtl) approach - looking for location of specific dna bit on genes that might be associated w/ particular behaviors. Both identical and fraternal, raised together or apart. Most personality traits have 40-60% heritability estimates unconscious - contains all drives, urges, or instincts outside awareness but nonetheless motivate most speech, thoughts, feelings, or actions. Unconscious forces motivate mind human mind = 3 distinct provinces /regions that control & regulate impulses.