Researchers have found that smiling is something: 1. we learn to do as babies. 2. we learn to do in childhood. 3. that means different things in different countries. 4. that is innate; we don't learn to smile, we just do it.

4 - That it it innate; we don't learn to smile, we just do it.

Smiling is produced when neuronal signals are transmitted to the facial muscles whenever endorphins are produced.

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.  

the earthquake in haiti was a magnitude of 7.0 according to the u.s geological survey yet the smaller earthquake in haiti killed more than 200,000 and left more than 1.2 million people homeless. the chile earthquake was a magnitude of 8.8 and 500 times more stronger but chile's earthquake only injured 712 people.