I think all group runs can be categorized in three general categories, with sub categories available by combining any two of the general categories, creating a potential for six types of group run dynamics.
The most commonly known and recognized group run dynamic category is the Competitive dynamic. This occurs in every race, kind of by definition. You are in competition with the guy/gal next to you, behind you and - heaven forbid! - ahead of you. This type of dynamic is also apparent in more informal group runs where a person or two is determined to run at the head of the group, or to maintain a position over another runner. It's not necessarily a bad thing, in fact, I would argue that it is a good thing, provided the competition is in good spirits and both(all) parties know there is a competition occurring. ("Race you to the top of the hill!")
A second dynamic is the Collaborative. The Collaborative dynamic is evidenced by encouragement, teamwork and other non-A-Type competitive activities. If a Competitive dynamic can be expressed as Martian (a la "Men are from Mars, Women are from Venus"), Collaborative run dynamics are Venusian. Typically a Collaborative dynamic should be present in all training runs, as the group as a whole is usually interested in getting all individuals across the goal of readiness for the upcoming event. The ultimate Collaborative runner is the pacer; all effort is given to getting the other runner to their goal.
A Collaborative - Competitive sub-dynamic presents itself in every relay race and also can be present in individual races. The combination in a relay is obvious; you are competitive as a team and collaborative within the team. Less obvious is the dynamic at work in an individual setting. It manifests itself in a race such that you as an individual are competing to the best of your ability, yet you still are rooting for your fellow runners to be their best - even if that best is better than you. A strange situation for A-Types like myself, to be sure, but I hear that dynamic is reasonably common in Venusian types. Me? I push competitors into bushes in order to win. I'm very Martian. :-)
The third and final general dynamic is the Comparative. I tend to fall into this dynamic on nearly every run, either as part of a group or solo. The Comparative dynamic manifests itself as a low-grade competition; more along the lines of "I can do that." kind of thing when comparing to others. It also comes about in comparing your current performance to your own past performances: "I did this route last month in 38:05, let's see if I can beat it." Typically that is an OK thing. Where it isn't an OK thing is when the runner falling into the Comparative dynamic fails to take any mitigating factors into account. (OK, me.) I neglect to account for current mental and physical health, aging, weather or anything and hold myself to the standard that I should always be better than before.
The most competitive, and probably the most damaging, too, dynamic is the Competitive-Comparative. In this dynamic, the runner is competing with others, AND comparing performances. This is all well and good provided the runner competes and compares favorably. Unfortunately, if either or both aspects fail to meet standards, the mental toll can be... ungood. I speak from experience. Too many of my runs/races have fallen into this category. I think it contributed mightily to my demurring on any races in the last couple of years.
The Collaborative-Comparative dynamic is probably the healthiest of them all. I see it as comparative in comparing against past performances, and collaborative in getting everyone to exceed their comparator. It excludes interpersonal comparisons and any animosity that can bring and has the potential of bringing out the best in every runner. I need to work on making all my runs this year Collaborative-Comparative.
What do you think? Are there other categories? Do you fit one or another?