There has been little change in public awareness of either synthetic biology or nanotechnology since previous surveys, according to this 2013 poll of more than 800 U.S. adults. In the poll, 23 percent of adults say they have heard a lot or some about synthetic biology, compared with 31 percent who say the same about nanotechnology. The most common associations that respondents make with synthetic biology are that it is unnatural, man-made, and artificial or that it has to do with reproducing life.