There is a cognitive limit to the number of people with whom one can maintain stable social relationships. This limit has suggested to be 150 and is known as “Dunbar’s Number” named after the British anthropologist Robin Dunbar. Dunbar’s research implies that for a group to sustain itself at the size of 150 requires significantly more effort that must be spent on the core socialization to keep the group functioning. The message for start-ups is that many things that are easy and happen naturally when they are small change and require conscious effort once you start really growing. It’s the time when the leadership together with the whole team need to step up the culture and communication game.