 A rapid increase in blood alcohol concentration (BAC) is most consistently associated with the likelihood of a blackout.However, not all subjects experience blackouts which implies that genetic factors play a role in determining central nervous system (CNS) vulnerability to the effects of alcohol.The former may predispose an individual to alcoholism, as altered memory function during intoxication may affect an individual’s alcohol expectancy, one may perceive positive aspects of intoxication while unintentionally ignoring the negative aspects.