It is 8 people per group (including myself). So if you are a smaller group there is a high chance that your group will be filled with other people. The reason that it is limited to 8 people per gorilla family group is to reduce behavioural disturbances of tourists to the gorillas in an effort to maintain conservation measures as well as to minimise the risk of human-borne diseases being exposed to the gorilla and lastly, to conserve the wild forest and the other creatures that live there.