Science of Laughter

FILE - In this Nov. 9, 1967 file photo, U.S. President Lyndon B. Johnson, munching on a cookie, and George Meany, president of AFL-CIO, laugh at a speaker's remark during the first annual Jewish Labor Committee Human Rights Awards dinner at the Sheraton in New York. Laughter is a serious scientific subject, one that researchers are still trying to figure out. (AP Photo/Marty Lederhandler, file)