Diversity in teamwork is advantageous in almost all regards. Diversity in training and skill set allows for teams to approach the problem from different vantage points, which allows for a deeper and more comprehensive understanding of the problem. Diversity in personality types also provides unique problem-solving techniques, as well as background experience.
Stanford University has collected records of team activities in their mechanical engineering program for the past 25 years, according to ASME. The records indicate that diversity in teamwork overwhelmingly contributes to the overall success of the project, especially when the group is composed of a widely diverse range of individuals with technical, psychological and emotional differences.
Diverse teams completed their projects more successfully than those composed of individuals with similar backgrounds and personality characteristics. However, it took the diverse teams longer to complete their project.
An advantage for widely diverse teams include the possibility of acquiring a new skill set. Working with individuals with different backgrounds forces one to cultivate an understanding of that person's background. This often contributes to learning a new skill or forming a deeper understanding of another culture or way of thinking.
The most cited disadvantage of teamwork is personality clashing. Sometimes it is difficult to work with a person whose personality does not mesh well with others, but these differences can usually be overcome when both parties are willing to compromise.