This quiz can be used to discover the zygosity of your twin children. The results of this quiz have a 92% chance of correctly determining your twin children’s zygosity. If you would like to confirm their zygosity we recommend a DNA zygosity test.

The following questions ask how alike your twin children were when “about one year of age”. Please choose the most fitting answer for each question.

Were your twin children “as alike as two peas in a pod"?

  1. As alike as two peas in a pod
  2. Usual sibling similarity
  3. Quite different

Were they mixed up at that age?

  1. Yes, very often
  2. Now and then
  3. Never

By whom were they mixed up?

  1. Parents
  2. Relatives or neighbours
  3. Others
  4. Nobody

The answers for each question are numbered. Add the answer number for each of your chosen answers to get a score from 3 to 10. Use the final score to find out your twin children’s zygosity.

A final score of 3 to 6 indicates your twin children would be monozygotic.

A final score of 7 to 10 indicates your twin children would be dizygotic.

Twins Research Australia

Address: 3/207 Bouverie St
Carlton, Vic 3010


ABN: 84 002 705 224

Twins Research Australia has received continuous funding from the National Health and Medical Research Council (NHMRC) since 1981, most recently through a Centre of Research Excellence Grant (2015-2022). TRA is administered by the University of Melbourne.

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