How does the type and length of contact affect the development of primary groups

The answer is: Time, organization, and size

As the length of contact increased, the more time you would spend with the groups. This often correlated with the increase in size of the organization (even though larger organization tend to develop its own members division and not all members would know one another)

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.