Adjunct Professor, Institute for Safety, Compensation and Recovery Research and Department of Epidemiology and Preventive Medicine, Monash University

First published in Thomson Reuters Inside OHS, the supplement to Occupational Health News, February 2015

Recently a board of which I am a member had a planning day. We had an excellent presentation by David Chalke from AustraliaSCAN about the future, including the loss of faith in institutions, something that is happening now, and that we can expect to see more of.

Instead of taking advice from governments, business leaders, unions and others, Australians determine their attitudes and beliefs from sources they have chosen to follow, reinforced by ‘friends’ around them.

In consideration of the number of ‘friends’, Chalke made reference to Dunbar’s number. 1990s anthropologist Robin Dunbar proposed that there was a correlation between average brain size and the average social group size in primates.

According to this theory, extrapolating from research in primates and relating it to human brain size it turns out that the number of stable relationships we are capable of sustaining is between 100 and 250, and 150 is usually adopted – Dunbar’s number.. Groups greater than 250 “require more restrictive rules, laws, and enforced norms to maintain a stable, cohesive group“.