There's a HUGE distinction missing here: People(not 'the rich') lose incentive to pursue wealth when there is none to obtain. People(not 'the poor') lose interest in obtaining wealth when it is given to them for no reason. It's basic psychology, people will take the easy way out if they can and they'll refuse to work towards something unobtainable.

This is one of those things that sounds bad when you say it, but is actually true, to a point anyway. The last part is only partially true. Poverty is one of the most complicated social issues in existence. But it is definitely true that receiving cash gifts, whether from the government, family, or otherwise, is proven to have negative effects on the economic productivity of the receivers of such gifts.

When have conservatives said this