In the field of expensively produced reports "scientifically proving" something that everyone already knew, the 1989 NHTSA report on "Sudden Acceleration Incidents", as chronicled by PJ O'Rourke, clearly stands out as the leader:
In the twinkling of an eye (by the standards of bureaucratic time, which is slower tan geologic time but more expensive than time spend with Madame Claude's grils in Paris) the thing was done. On March 7, 1989, the DOT-NHTSA-ODI-TSC-OPSAD-VRTC (you'd think the initials alone would be enough to slow down any rnaway cars) effort produced an eighty-one page report written by an eight-man group of engineering savants with more than fifty years of college among them. This document presented evidence from exhaustive experiment and analysis that proved what everybody who understands how to open the hood of a car had known all along about SAIs: "Pedal misapplications are the likely cause of these incidents."
Yes, the dumb buggers stepped on the gas instead of the brake . . . the truth was out at last. The government had released a huge report showing that there was no such thing as unintended acceleration in automobiles. Stand by for huge government reports on fairies stealing children and poker wealth gained by drawing to inside straights. Meanwhile cars did not fly away of their own accord. They could be safely left unattended. You can fold up the camp cot and quit spending nights in the garage keeping an eye on the family minivan.
However, it now has some competition:
Children who play sports video games on the Nintendo Wii burn more calories than they would playing regular video games, but not as many than if they played the actual sports, a new study shows.