When the stress of the war in Iraq becomes too severe, the Pentagon has a suggestion for military families: Learn how to laugh. With help from the Pentagon`s chief laughter instructor, families of National Guard members are learning to walk like a penguin, laugh like a lion and blurt ”ha, ha, hee, hee and ho, ho.” No joke. The instructor, retired Army colonel Scott, 57, is certified as a laughter training specialist by the Ohio-based World Laughter Tour, a group that promotes mirth as medicine. It touts scientific research that suggests chuckling can boost the body`s immune system and decrease stress hormones. The laughter program was Scott`s idea. It costs the military virtually nothing, because Scott already travels to states as a director of military family support policy. He has taught National Guard family group leaders in Alaska, Kansas, Oklahoma, Texas and Idaho, and will do so in Michigan, Pennsylvania and Florida, he says. Another laughter trainer is working with folks in North Carolina. ”We believe our program prevents hardening of the attitudes,” says Scott, in one of his wordplay aphorisms that beg for a rimshot. The founder and chief executive of the World Laughter Tour is psychologist Steve Wilson, who calls himself ”Cheerman of the Bored.” ”The guiding principle is to laugh for no reason. And that`s one of the reasons it works so well for military families,” Scott says. ”There`s a lot they have to be stressed over, a lot of worries, a lot of concerns.”