A person's attitudes, habits and achievements are claimed to converge on the mean of their closest associates.
The maxim is among the most repeated in the genre and among the least supported. Peer effects exist and are measurable where assignment is random, as in roommate and squadron studies, at magnitudes far below averaging. The number five appears to be rhetorical, and the selection problem is fatal to the observational version.
In practice
- A high-performing team raises the output of its members, by less than the folklore and more than nothing.
- A person who changed their circle and improved may have changed their circle because they were improving.
- Possible explanations
- The explanation offered is social contagion: habits, standards and expectations are absorbed from the people one spends most time with.
- In its favour
- Peer effects are real and measurable where assignment is random, as in roommate and squadron studies, so the underlying phenomenon exists.
- Against it
- No source has been found for the claim or for the number five, it has never been tested, and the measured peer effects are far smaller and more domain-specific than an average of five people would imply.
- Standing
- Testimonial evidence selected on success, with no comparison group. No source has been found for the claim or for the number five, and it has not been tested. Peer-effects research finds real influence, much smaller than this implies and heavily confounded by the fact that people choose their associates.
- Subject
- Sociology & Culture
- Essay
- Proverbs that recur across cultures