Team Vs. Group: How the behavior of members differs?

Members of a team appreciate that their own (individual) success is determined by the collective performance of everyone. They have a much greater motivation to help and support those team members whose performance may fall behind ... for whatever reason.

Perhaps an under-achiever is new and needs a buddy or a mentor to help them get established. Maybe there are environmental reasons for poor results. Other members are likely to find ways to help them raise their game.

For a group member however, his status and reward depend only upon his individual performance. Generally speaking, if he gives time or resources to another group member there is no benefit in it for him.

If this effort takes his attention away from his own performance he might even suffer as a result.