The make-up of a team, including the mix of cultures and personalities, can make or break its effective output and viability. A homogeneous team would include people who are as similar as possible, with similar points of view, learning abilities and life experiences. Heterogeneous teams include a mixture of races, genders, cultures and ages that provides a wider range of life experiences and opinions. Studies in education, psychology, sociology and business reach conflicting conclusions about whether homogeneous or heterogeneous team composition provides stronger results, which is unsurprising given the vast number of studies and variables to discuss.
Homogeneous Team Benefits
Homogeneous teams --- teams made up of people from the same race, gender, social background and age --- often provide equal access and participation of members, as there is less chance for exclusion. Members of a homogeneous team will have an easier time of comprehending each other's verbal and nonverbal communications and will have more shared experiences in common. The similarities can, to some extent, avoid misunderstandings, prejudices and, arguably, speed up work processes and the completion of tasks, although this is not always the case as personality conflicts can occur within homogeneous teams as easily as within heterogeneous teams. There is evidence, such as within educational programs for gifted students, that homogenising groups on the basis of intelligence provides a good environment for high achievers to progress at a faster pace than is possible in mixed ability groups.
Homogeneous Team Disadvantages
Many studies, for example "Cognitive effects of racial diversity" by Samuel R. Sommers, et al, in "The Journal of Experimental Social Psychology," show that the lack of diversification in a homogeneous group stifles creativity and information processing. It is, perhaps rightly so, very difficult to form homogeneous teams without causing feelings of exclusion to minorities, be those racial or gender.
Heterogeneous Team Benefits
Having a mixture of cultures, abilities and life experiences can create a stronger dynamic within a group. Individuals can be "experts" in roles; leader, innovator, communicator, peacekeeper and so on. This can be an organic development or roles can be provided on formation of the group. Studies, such as "Cognitive effects of racial diversity" (see Section 2) suggest a higher degree of creativity and information processing in heterogeneous teams.
Heterogeneous Team Disadvantages
With groups that have mixed learning styles and abilities, group members can find it difficult to communicate and understand others' ideas and information. Having a minority of any sort, whether it is a particular gender, race or age group, can lead to feelings of isolation and so loss of confidence or status within the group. Members with different learning speeds and styles can find themselves left behind if communication methods settled upon suit the majority of the group, but not the whole.
The suitability of homogenising groups depends very much on the purpose of the team. A team intended to promote cutting edge developments will benefit from grouping high intelligence individuals, so being homogenised by intelligence, but it would also benefit from a mix of cultures and life experiences. Having methodologies for communication and working processes in place early on in the team's formation can mitigate many problems in both homogeneous or heterogeneous teams.