This is not a post about Tuckman's Stages of Group Development. We will, however, reference his work in tackling the question "What is team development and who's responsible for it?"
Tuckman gave us the forming - storming - norming - performing phases. If you've ever been a charter member of a team, you've experienced these phases firsthand. They are unavoidable, and every team experiences them. However, the amount of time spent in each phase is something you can impact. Briefly:
You can move through the forming phase faster if individual members understand their roles, responsibilities and value to the team. Egos and personal agendas will be less obtrusive if individuals are ready, willing and able to share power and work toward a common goal.
The storming phase is one that should be embraced and not avoided. Healthy conflict, in fact, should be a group goal. Teams that attempt to avoid intra-group disagreements inevitably end up with members who are disenfranchised and never fully committed to the decisions and initiatives of the team. To storm in a productive way, team members must show respect and tolerance for each other. Expectations for how team members interact should be established early on and in a formal manner.
Next is team norming, the phase where team development really takes place. This is the phase where team members begin working cooperatively, even collaboratively, to achieve their shared goals.
High performing teams experience occasional dissent. They mine for diverse points of view and work through that healthy conflict together, ever mindful of their shared purpose. Members challenge and motivate each other. The forming and storming phases are repeated when new members join the team or other significant changes occur that impact the team dynamic.
Knowing that this is the way a team will progress should not be justification for leaving the team to its own devices when it comes to development. There's more that team leaders and members can do.
To develop is "to bring out the capabilities or possibilities of; bring to a more advanced or effective state."
A team, of course, is "a number of persons associated in some joint action."
Team development, then, is bringing out the capabilities of the people associated in a joint action, making them more effective.
Note that this definition forces a focus on individuals. Development of a team goes beyond the team itself. In order to "bring out the capabilities or possibilities" we have to get to the individual level.
Think of it this way. You can't have a flourishing garden without individual plants that are healthy and nourished. A symphony only sounds good if every instrument is tuned. You can't win football games if only the quarterback is playing.
Individual development is the key to team development. Empowered individuals have more to contribute to a team.
Every person with the authority, influence or ability to support individual development is, ultimately, responsible for team development.
Every member of the team is also responsible for team development. If team members challenge one another, they are developing each other. If team members respect and trust each other enough to engage in healthy conflict and explore diverse points of view, they will develop each other. If team members focus on developing themselves and others, they will invest more in the work of the team and produce better outcomes for the team and for each individual.
When individuals get left out of the equation, teams flounder and fail. Expecting people to altruistically defer their own development needs in pursuit of "team development" is counter-productive and unnecessary.