What is a 'Peer Group' A peer group is a group of individuals or entities who share similar characteristics and interests. Peer groups, in the case of people, have characteristics which include similarities such as socio-economic status, level of education, and ethnic background and so on amongst its individual members. A group of individuals or entities who share similar characteristics and interests. Peer groups, in the case of people, have characteristics which include similarities such as socio-economic status, level of education, and ethnic background and so on amongst its individual members.