You Hiccup Because of Evolution
Why do we hiccup? Evolution. Our amphibian ancestors needed to be able to switch back and forth between breathing air with lungs and pushing water over their gills. The nerve signals that regulates this process of snapping the epiglottis shut and sucking in water is identical to a hiccup. We still have the ability but no longer have the gills to make it worth anything.
Via our partner page EvolutionEvidence.org.
Bonus fact: Charles Osborne holds the Guinness World Record for the longest continuous hiccup at 68 years. http://en.wikipedia.org/wiki/Charles_Osborne_(hiccups)
Read more on our evolutionary vestiges: