Risk factors for heavy drinking operate primarily through intermediate characteristics that relate to environmental events and genetic influences to impact on the development of heavy drinking and alcohol use disorders (AUDs). One such pre-existing phenotype is low Level of Response (LR) to alcohol, where individuals who require higher doses of alcohol to achieve an effect are more likely to develop AUDs than those who react more intensely to ethanol. This trait can be measured as less alcohol-related change in positive (e.g., feeling high) and negative (e.g., feeling dizzy) subjective feelings of intoxication, hormones, and EEG measures at a given blood alcohol concentration (BAC), or as less effect per drink on a retrospective questionnaire. Low LR is seen in ~40% of the children of alcoholics, but only ~10% of controls, and the heritability of this trait measured by questionnaire is 40%-60%. Critically, LR predicts later heavy drinking and the negative impact of alcohol abuse and has been demonstrated to be an effective target for directed alcohol management intervention, yet despite its clear translational importance, the biological underpinnings of this trait have yet to be fully characterised and replicated. The proposed recall experiment will replicate novel work from collaborator MS and colleagues concerning the functional underpinnings of LR status and extend it in an independent collection (ALSPAC) with access to comprehensive genotypic data, life-course phenotypic data and prospective follow-up of alcohol related events and measures.