Researchers stroked babies' faces with a paintbrush while they watched the same thing happening to a baby in a video. How long the babies in the experiment watched the screen gave clues to what they were thinking.
Courtesy of Maria Laura Filippetti
Public school student Julio Valenzuela, 11, grimaces as he gets a vaccination before the start of the school in Lynnwood, Calif., on Aug. 27. Vaccines are required for school attendance.
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