Briefly explain the steps involved in conducting twin studies

What will be an ideal response?

(1) Pairs of identical twins are compared with each other on a particular characteristic, as are pairs of (same-sex) fraternal twins; (2) these two correlations are compared with each other. If identical twins are more similar to each other than fraternal twins, it must be due to the differences in genetic similarity. (This conclusion could not be drawn if parents treated fraternal twins differently from identical twins.)