Starting in the 1960s, a growing body of evidence began to strongly support the view that all organisms, including us, are biologically prepared for certain behaviors, and even that specific forms of learning are not totally open-ended, but instead are biologically prepared or constrained.

To take but one prominent example, it is no coincidence that across all cultures, babies learning their native language progress through the same stages in the same sequence, and on a very similar timeline, regardless of how a given culture approaches language training.

What does our growing understanding of our evolutionary history (as bipedal, social, communicating, visually-orienting, hunting/gathering primates) forecast about organizational behavior? In a wonderful Harvard Business Review article from a few years back entitled “How Hard-Wired is Human Behavior?” author, business school professor, and dean Nigel Nicholson offered some interesting observations and speculations about biological constraints on the organization.

The size of the “tribe”

 Anthropologists studying primitive cultures discovered years ago that the maximum size for an effective functional social unit (tribe) is around 150. Within that range, it is possible for individuals to know and relate to each other, to feel a sense of personal obligation to the group, and to sort out the social hierarchy. Beyond that number, called “Dunbar’s number” in honor of the anthropologist and evolutionary psychologist who first proposed it, there is a dramatic drop off in individual social responsibility, subgroups form, conflict increases, and the group usually splits if it can. 

From a descriptive/observational perspective, organizations seem to do better in every significant way if the workplace is small. The “malaise of the factory” seems to grow in direct proportion to the size of the factory, beyond Dunbar’s number. The artificially constructed society of the 5,000-person factory is commonly dysfunctional in a wide variety of ways. We have seen a resurgence of the small-plant, mini-mill as opposed to the mega-factory of the past era, in part inspired and made possible by advancing technology, but also in part inspired by the manifest problems of the huge, amorphous factory. Other things equal, smaller plants of 150 or fewer employees just perform better.

The size of the team

There is also an extensive research literature in social psychology and group dynamics on “small group process.” A bottom-line conclusion from this research is that the optimal size for a working group (e.g., decision-making group, discussion group, work team, safety committee) is in the 5-12 range, centering around 7. That number, long known to be optimal for brainstorming groups, is also the typical average span of control (number of direct reports) for supervisors and managers.

For a group to develop into a cohesive unit, with a sense of common purpose and commitment to the whole, it is important that the team not be too large (too little sense of personal responsibility) or too small (below critical mass for synergy). Organizations with work units within the “proper” 5-12 size range do best, in terms of essentially every significant measure of productivity and employee satisfaction.

Anthropologists note that the typical family-unit size of our ancestors, as well as their hunting-group size, was in that very 5-12 range. Apparently we are wired to build close, committed relationships of high trust and interdependence in groups of about that size.


It is obvious that organizations of all sorts are hierarchically organized. Even companies that have made much of flattening the hierarchy, such as W.L. Gore Associates, Harley-Davidson, and the now defunct Saturn Corp., still have hierarchy.

As a consultant in the area of self-directed work teams, I can tell you they still have leaders. Changing the title of the supervisor does not eliminate leadership over such teams. Someone must be the point of contact, and have the responsibility of linking the team to the rest of the organization. Call that person facilitator, coordinator, team resource or whatever – that person provides direction and support for the team and in some real sense functions as the daily leader.

In our evolutionary history, truly leaderless groups are rare, if not nonexistent. The “alpha male” (sometimes female, and if so, often the mate of the deceased alpha male) occupies a position in bands of social primates, including homo sapiens, that is conceptually quite similar. He/she is the boss – the team leader, department head, general manager, CEO.


Despite widespread commitment to innovation, creativity, and the like, it is widely noted that most organizations tilt strongly toward caution and conservatism rather than risk-taking, especially to the extent they have been successful. Caution and conformity are rewarded more than deviance from the familiar, in most cases.

Nicholson suggests it would have been most adaptive for our ancestors to conserve and protect resources that promoted their survival and procreation (wives, cattle, land) and to only “risk it all” if seriously threatened. Thus there might be a biological/evolutionary base for the overwhelming appeal of “calling conservative plays when your team is ahead.” It may be a core reason why flexibility in the face of changing conditions (e.g., new technology, new competition) is historically so hard, especially for organizations that have been successful. The biologically predisposed strategy is called win-stay, lose-shift, and it is seductive indeed.

The biological leash is long and flexible. But our evolutionary history does predispose us to act in certain ways, and to find certain structures more comfortable and natural than others. It is very instructive to be aware of those imperatives.