A mom of ten-year-old identical twin girls called to ask for advice and reassurance. The mom said that both girls are doing well in their separate classes at school. She has tried diligently since they were quite young to direct them toward separate activities. Sometimes she is successful and other times frustrated. We talked about how similar monozygotic twins’ interests and skills often are due to their identical DNA. Both girls play the same musical instrument and share a group of friends. The mom has had some success getting them into separate afterschool activities; however, their enthusiasm for divergent experiences seems to diminish over time.
Also, the twins often make joint decisions about their activities. When the mom first suggested sleep-away camp, both voiced their excitement. Then a few weeks later, one of her daughters said that she changed her mind about going—so her sister said she would not go either. The mom also described how they keep score regarding who has what. One of the girls wanted an alarm clock, so her mother got one for her. The mom thought about buying a clock for each girl but decided that would be redundant since the twins share a room. However, the daughter who did not ask for or receive the alarm clock became preoccupied with the idea that her sister got something and she did not. The mother finally got fed up with the bickering and gave her other daughter an alarm clock just to put an end to the squabbling.
When she’s less frustrated, the mom realizes that the girls will most likely be more motivated to go in separate directions in their teenage years. However, at this developmental juncture, she has to put up with the complaints about unfairness and the undue influence the girls have on one another’s decisions—which currently appear to be shared and inviolable.