Impulsivity, hunger, and early life deprivation
Abstract: Impulsivity refers to the valuation of future rewards relative to immediate ones, and has been implicated in a range of societal issues such as drug use, crime, educational attainment, and obesity. From an evolutionary perspective, we should expect impulsivity to be sensitive to the current state of the organism (for example, hunger), and also its long-term developmental history. There is some evidence that both current hunger and early life experiences are individually associated with impulsivity, and we conducted three studies which aimed to investigate whether these two factors had an interactive or additive effect on impulsivity.
In study 1 (n=95) and study 2 (n=93) participants’ hunger was manipulated by having them skip breakfast or have breakfast as usual. They then completed an impulsivity task and measures of early life deprivation. Study 1 incorporated a novel experiential discounting task to measure impulsivity (participants actually receive rewards and have to wait for them) and study two utilised the traditional hypothetical delay discounting task as a measure of impulsivity. Study 3 built upon the first two by recruiting participants with a broader range of childhood deprivation.
We conducted a survey (n=330) in which participants reported their current hunger, completed two measures of early life deprivation, and completed a hypothetical monetary discounting task. The findings from our three studies provided mixed evidence as to whether hunger and early life deprivation have an interactive effect on impulsivity, and so we meta-analysed our data, finding evidence for main effects of hunger and early life deprivation individually, but not for an interaction. These findings have important implications for informing potential interventions aimed at improving societal issues such as drug use and crime.
Caroline Allen is a Psychologist with broad interests in the evolutionary underpinnings of human behaviour. She completed her PhD at the University of Stirling and currently works as a Research Associate in the Institute of Neuroscience at Newcastle University. Her current research is focussed on investigating the ways in which hunger alters behaviour and cognition, and how other factors, such as your early life experiences, may interact with this. She is currently working in a comparative lab group, where there is also a focus on designing tasks for human participants which are analogous to those used to study behaviour in other species.