The researchers were out in the parking lot, and they were counting people as they came in and out of the store, and they noticed that when the volunteers stood in front of both doors, people stopped coming out of the store at all.
Os pesquisadores estavam no estacionamento contando as pessoas quando entravam e saíam da loja, e notaram que quando os voluntários estavam na frente de ambas as portas, as pessoas pararam de sair da loja.