In his study, Evans tracked 341 participants over a 15-year period, and tested them at ages 9, 13, 17 and 24. Short-term spatial memory was tested by asking adult study participants to repeat increasingly complex sequences of lights and sounds by pressing four colored pads in the correct order -- similar to the "Simon" game. The adults who grew up in poverty had a diminished ability to recall the sequences, compared to those who did not. "This is an important result because the ability to retain information in short-term memory is fundamental to a host of basic cognitive skills, including language and achievement," the study said. Although the participants were assessed on this measure only when they were adults, this test had the strongest association with childhood poverty of the four measures. Helplessness was assessed by asking the participants to solve an impossible puzzle. Adults growing up in poverty gave up 8 percent more quickly than those who weren't poor as kids. Previous research has shown chronic exposure to uncontrollable stressors -- such as family turmoil and substandard housing -- tends to induce helplessness. Mental health was measured with a well validated, standardized index of mental health with statements including "I argue a lot" and "I am too impatient." Adults who grew up in poverty were more likely to agree with those questions than adults from a middle-income background. Chronic physiological stress was tested by measuring the participants' blood pressure, stress hormones and body mass index. Adults who grew up in poverty had a higher level of chronic physical stress throughout childhood and into adulthood. - www.sciencedaily.com