Everyday conversations are constrained to you and four people. Whether at work, a dinner table or a cocktail party, we tend to gravitate towards groups of 2-5 people. Even Shakespeare’s plays usually don’t have more than 4 speakers engaged in conversation at once (if we count choruses as one speaker). The steadiness of this constant is almost uncanny. But why and how is four other people the maximum size for our conversations?
Psychologists have developed several hypotheses to explain this limit. Perhaps the most obvious one is that we simply can’t hear well enough if we are in a larger group. The idea would be that we can’t process the sound of four speakers into actual meanings if they happen all at once. Another immediate explanation is that of the limitations of our short-term memory. The claim would be that four people talking creates too much information to be processed at once. Another explanation is that our ability to model other minds is constrained to four.
The last explanation is championed by Oxford professor Robin Dunbar¹. He explains that when we talk with one another, we constantly model the mind of the others. For instance, we have to know how much they know, as to not waste time disclosing irrelevant information. If Bob and Alice are married, they don’t need to emphasise that fact to life-long friend Charlie. However, to Derek, who has just met them, Alice might very well say “my husband, Bob”. There are more reasons for modelling the minds of others in a chat, such as whether they are bored by my story or whether they are likely to agree? It turns out, however, that evolutionarily there was little need to precisely model more than four minds at the same time, claims Professor Dunbar. As a consequence, we have never developed in this direction.
In the era of remote work, we have to adapt to these facts of nature. One way of adapting is to create such tools and such an architecture that allows for this. Just as we put 3-4 armchairs around a table in a lounge (not 9 or 17!), we have to find ways of doing that online.