There are a few positive things in life that are contagious and laughter is one of them. The first thing Jameson laughed at was a real sneeze of mine. I think he was about 4 and a half months old. So, we proceeded to to increase the laughter with fake sneezes! Here's Daddy & Jameson. Daddy, of course, had the sneezes and Jameson had the giggles.
(almost 5 months old)