twin studies

  1. L

    Twins raised together and twins raised apart

    Greetings All, I am examining smoking behavior in a sample of twins raised apart and together.I have repeated measures at different time points asking participants if they smoke or not. I also have a question about whether the participant grew up in a household where parents smoked. My...
  2. L

    Is there a R package for analyzing twins raised together and apart?

    I have data from a clinical study on samples of twins raised together and apart. I have not found much resources for this type of analysis. Can anyone point me in the direction of these type of information or R package? CHEERS
  3. A

    Correlations between twins - who is X and wo is Y?

    I have some data on twins (all fraternal) and I'm trying to see if there is any correlation between them on several measures (e.g., body measurements, behavioral test results, etc). My question is, how are twins designated as X's and Y's in twin studies that use correlations? That is, which...