Since its earliest years, the co-operative movement has celebrated the diversity of human society and sought to bring together people of different social groups and classes, different races, different political affiliations and different religious beliefs. This welcoming of human diversity, in all its forms, is a key characteristic of co-operatives and finds expression in the 1st Principle.

No person applying for membership of a co-operative should be refused membership because of any personal characteristic. The 1st Principle's prohibition against discrimination is absolute. The inclusion of the words "gender, social, racial, political or religious discrimination" to illustrate the categories of people who may be unjustly treated does not limit the principle of granting membership rights without discrimination. Listing examples of categories of people who may be discriminated against in an unequivocal statement is an ancient rhetorical way of illustrating the 1st Principle's broad scope and extent.4 The United Nations' Universal Declaration of Human Rights and 1966 International Covenant on Civil and Political Rights take a similar form.5

Society has changed since the Co-operative Principles were last re-formulated in 1995. There is a welcome global trend to celebrate human diversity and a growing commitment to the right to equality of treatment for all people. "Without discrimination" in this Principle imposes a duty on co-operatives to rise to the challenge of including all people in membership, a challenge that is particularly acute in countries and cultures where discrimination on grounds such as religious belief, ethnicity or race, gender or sexual orientation is a cultural norm.

In order to be open to all people, co-operatives may need to take positive action to be inclusive. Co-operative premises may need adaptations to be accessible to people with disabilities. People who suffer blindness or sight impairment may need special assistance to use a co-operative's services. New members who have not had the benefit of formal education may need to be given opportunities to develop literacy and numeracy skills in order fully to participate as members.

Any form of discrimination based on age also needs to be challenged. Democratic renewal through training opportunities to encourage younger members to stand for election is preferable to arbitrary age barriers designed to exclude older members from active participation. Co-operative membership is in need of constant renewal. Every co-operative business needs new, younger members in order to be sustainable. The danger of control by older members, effectively stifling the engagement of a younger generation, should be recognised. A co-operative is only as strong as its next generation of members. Democratic structures and representation should reflect the demographics of a co-operative's membership. The co-operative movement in some countries has specifically encouraged the development of youth and student co-operatives to engage the next generation. Establishing co-operatives in schools and universities may be a way of encouraging young people to experience and appreciate the benefits of co-operative enterprise that will lead to their subsequent engagement in the wider co-operative movement.