Question Sheet: Double take


Before reading:

  1. What distinguishes twins from other pairs of brothers and sisters?
  2. What do you think scientists hope to learn by studying twins?
  3. What makes twins so similar? Having similar genes? Growing up in the same

    household at the same time — sharing all household experiences at the same age?

  4. What do you expect are the advantages of being a twin — and disadvantages?

During reading:

  1. What’s the difference between fraternal and identical twins? And what

    happens differently in the womb to give rise to one type of twins or the other?

  2. What is DNA and how many chromosomes do people have. (Hint: How many sets

    are there?)

  3. The University of Minnesota study also tracks “virtual twins.” What are


  4. Name one major finding from the twins study.
  5. How do twin differences change with age?

After reading:

  1. What kinds of information can the study of twins offer that might apply to


  2. In the nature vs. nurture debate, what does twin research tell us about the

    importance of nurture?

  3. When women go to fertility clinics and end up having multiple babies — what

    kinds of twins or triplets or quadruplets do these tend to be: fraternal or


  4. Even identical twins can have different traits — from height and health to

    personality. What factors can lead to such differences?

  5. Some scientists study twins who were separated at birth and raised by

    different families. What can these investigations tell us about the role of

    genetics in people generally? And why are twins so useful in identifying those



  1. How many twins are born each year, and does the number vary by country or

    ethnic group?

  2. Some families have many sets of twins. What information is there to suggest

    why that might happen?

  3. Twins can be far more costly to a family than just having two children a

    couple years apart. Why is that, and how much more expensive can twins be?

    (Hint: How useful are hand-me-downs?)


Write a small essay on how you think your life would be

different if you were an identical twin (unless you are one, and then write

about how you imagine your life would differ if you had been born a fraternal