The experience forces students to mature because they have to take responsibility for their own learning. They must be willing to live with discomfort when they find there's no one overarching perspective that will be the answer to their project. They learn how to work together not just to get a good grade but to take responsibility because the sponsor has a keen need for research on a particular aspect of a problem. They come to understand that it matters not just to that person but to other people. They have responsibility in the larger question, "how do we improve society and how do we improve peoples’ lives?"
Students also benefit from the demands that projects impose on them. They must work together well as a team; they must understand and anticipate the needs of many different people. That they understand the social complexity of a problem is an enormous gift project-based learning gives them. They realize there are many different stakeholders in these issues.