Agroup of rats was run through a maze for 12 days. on days 1 through 10, there was no food reward at the end of the maze, and the rats made many errors as they slowly moved through the maze. on day 11, researchers placed a food reward at the end of the maze. with the food reward in place, the rats ran the maze very quickly and with few errors. according to psychologist this experiment demonstrated a phenomenon called

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.