It has nothing to do with physical complications or whether they have the right partner or not, but a WA study has found that most people who do not have children are childless by choice.

The survey, by Edith Cowan University lecturer in psychology Bronwyn Harman, found three quarters of people without children had made an active choice to not have children.

While almost 30 per cent of the study said they may have children later in life, a similar amount said they simply were not maternal or paternal.

The other quarter of those surveyed were involuntarily childless for reasons such as being infertile, unable to carry a baby, not having a partner during childbearing years, genetic or medical issues, their sexual preference, having a partner that did not want children or leaving it too late in life.

Doctor Harman's study involved 330 adults, of whom the majority were women.