I've heard the same thing, but do you have a reference for this?
Re:Investment increases your risk
by ChristianMarks on Friday December 27, 2013 @11:25AM
(#6971230)
LMGTFY:
Anandi Mani1, Sendhil Mullainathan2, Eldar Shafir3, Jiaying Zhao4. Poverty Impedes Cognitive Function. Science 30 August 2013: Vol. 341 no. 6149 pp. 976-980 http://www.sciencemag.org/content/341/6149/976
http://www.theguardian.com/science/2013/aug/29/poverty-menta...
Research shows that the cognitive load associated with being broke amounts to a loss of one standard deviation in IQ. The mind is focused all right: only on making the rent and on nothing else, and under no circumstances on anything like starting a business.