Though much in the news today, scientific misconduct goes back at least as far as the ancient Greeks, according to an
essay in
The Nation by Charles Gross. The astronomer Ptolemy of Alexandria, Gross reports, may have pinched unacknowledged work by an earlier researcher, Hipparchus of Rhodes, who did likewise with discoveries made by even earlier Babylonians. Other miscreants may include Isaac Newton and Gregor Mendel, both apparently guilty of fiddling their data to produce more elegant results. In 1830, Charles Babbage went so far as to categorize the scientific wrongdoing he saw around him into "several species" including "hoaxing, forging, trimming and cooking," as quoted by Gross.
The essay concentrates on the much more recent case of disgraced cognitive researcher Marc Hauser, formerly of Harvard, but along the way traces the interesting history of the development of modern concepts of scientific integrity and misconduct. You can read it
here.