There is increasing evidence to suggest that chronic, severe stress during childhood can lead to changes in the brain’s reward circuitry that leads individuals to prefer short term gains and immediate gratification over postponed, long-term gains and pleasures.
So, for example, rather than save up money to start a business or for an exotic holiday or undertake a diet and fitness regime to improve one’s health and fitness, an individual who has undergone chronic, early-life stress may prefer the kind of instant highs obtainable from alcohol, smoking, junk food, gambling, casual sexual encounters and narcotics.
It is hypothesized that this dysregulation of the appetites may be linked to damage (caused by chronic childhood stress) to the prefrontal cortex which, in turn, reduces its ability effectively to send signals/chemical messages that would otherwise be able to inhibit the nucleus accumbens.
The nucleus accumbens is a region of the brain that drives our sense of desire, or, to put it more simply, makes us want what we want. And, if the prefrontal cortex is unable to keep it under control due to the factors explained above, it can run amok and, potentially, turn us into chain-smoking, alcoholic, drug-addicted, morbidly obese, gamblers and sex-addicts. Clearly, quite apart from other relevant considerations, this would not be good for our physical health (indeed, statistics show that all else being equal, those who have suffered severe and protracted childhood trauma, on average, die significantly earlier than those who have had more fortunate early life experiences).
In other words, if we have suffered significant early life stress we are at increased risk of impulsivity and of seeking and obtaining immediate rewards whilst ignoring the harm and potential losses such behaviour may cause us in the long term
EXPLAINING THE PRIORITIZING OF IMMEDIATE REWARDS OVER GREATER, LONG TERM REWARDS IN EVOLUTIONARY TERMS:
Such impulsive behaviour and prioritizing of short term gains due to the effects of excessive stress and of living in the constant anticipation of danger can be explained in evolutionary terms: If our ancestors were chronically stressed and perpetually feeling under threat because their survival was in danger due to scarce resources and/or because they could at any time be attacked and killed by a predator, it would have been evolutionarily adaptive to consume as many calories as possible when the opportunity presented itself (as there was no way of knowing how long it would be until the next meal became available) and to mate as early and frequently as possible (to maximize the chances of their genes being passed on), as well as to exploit opportunities to achieve other short term ‘wins.’
Indeed, in support of this idea, there exists research (Sweiitzer et al., 2008; Gianaros et al., 2011) to suggest that those from the lowest socioeconomic echelons of society have a greater propensity than those from wealthier backgrounds to opt for immediate rewards and instant gratification at the expense of forfeiting larger, future rewards.
Parental Education Predicts Corticostriatal Functionality in Adulthood. Cerebral Cortex, Volume 21, Issue 4, April 2011, Pages 896–910.
David Hosier BSc Hons; MSc; PGDE(FAHE).