When running through the airport, collin trips and spills all of his stuff out of his backpack. lots of people see collin trip and fall, but no one him pick up any of his stuff or checks to see if he is okay. the fact that others do not in this case is best explained by?

The fact that others do not help in this case is best explained by "bystander apathy".
The bystander effect, or bystander apathy, is a social mental wonder in which people are less inclined to offer assistance to a casualty when other individuals are available. The more noteworthy the quantity of onlookers, the more improbable it is that any of them will help.