Excuse or Scientific Fact?

Poverty and the dysfunction that accompanies it produces quite a lot of stress in people.  Children who are subjected to poverty and stress have trouble learning.  But many still believe that’s not true and that homeless children and children of poverty should be able to learn just as well as anyone else.  Perhaps this discussion will help clear up the matter somewhat. 

Stress produces many reactions in people, not the least of which is the production of adrenalin and cortisol by the body.  Cortisol is released in response to stress, sparing available glucose for the brain, generating new energy from stored reserves, and diverting energy from low-priority activities in order to survive immediate threats or prepare for the exertion of rising to a new day. However, prolonged cortisol secretion (which may be due to chronic stress or the excessive secretion seen in Cushing's syndrome) results in significant physiological changes. However, long-term exposure to cortisol damages cells in the hippocampus; this damage results in impaired learning. Furthermore, it has been shown that cortisol inhibits memory retrieval of already stored information.

(de Quervain DJ, Roozendaal B, McGaugh JL (August 1998). "Stress and glucocorticoids impair retrieval of long-term spatial memory". Nature 394 (6695): 787–90.)

(de Quervain DJ, Roozendaal B, Nitsch RM, McGaugh JL, Hock C (April 2000). "Acute cortisone administration impairs retrieval of long-term declarative memory in humans". Nat. Neurosci. 3(4):313-4.)

Two conditions that cause increasing cortisol levels are (1) Severe trauma or stressful events can elevate cortisol levels in the blood for prolonged periods; (2) Severe calorie restriction causes elevated baseline levels of cortisol.

(Smith JL, Gropper SAS, Groff JL (2009). Advanced nutrition and humanmetabolism. Belmont, CA: Wadsworth Cengage Learning. p. 247. & Moberg GP, Mench JA (2000). The biology of animal stress: basic principles and implications for animal welfare. Wallingford, Oxon, UK: CABI Pub. p. 377.) 

(Fichter MM, Pirke KM, Holsboer F (January 1986). "Weight loss causes neuroendocrine disturbances: experimental study in healthy starving subjects". Psychiatry Res 17 (1): 61–72.)

So, we’re no longer talking about some claim of dysfunction made by educators, looking for an “excuse for poor student performance”, as many have claimed.  We’re talking about a bodily reaction to the stress of poverty and homelessness that cause increased levels of a chemical that inhibits learning. 

Can we stop accusing educators of making excuses now?