It is very essential in any team to have some sort of enthusiasm regarding the project in order to perform their best and have the highest level of productivity. This can be certainly directed by the project manager in most cases. As explained in an earlier lecture, interpersonal skills are very important compared to the technical skills in many situations. This would require project managers to be able to lead both the group itself, the project flow and the group members, which means that the PM would need to control and manage different personalities in an efficient way and at the same time to motivate the group in order to achieve success and ensure that all outcomes meet the project requirements. As other replies mentioned above, PM should at first have a high level of motivation toward the project, then this would reflect eventually on the team. This includes staying with the group until late at night to complete a task to not miss a deadline, having good communication skills, act with fairness, etc.