Longitudinal 
              Twin Study (LTS) This longitudinal study began recruiting 
              twins in 1985 and recruitment lasted for a period of 7 years. The 
              oldest twins are now 17 and the youngest are 11. Each year the twins 
              are contacted for a different type of interview. We have conducted 
              home visits, lab visits, and telephone interviews that cover many 
              different aspects of human behavior and development. The wealth of 
              data from these studies has led to the publication of over 75 journal 
              articles and a book in 2001. 
            Center for Antisocial Drug Dependence: Genetics - Community Twin Sample  (CADD) For this project twins ages 12-18 
              and their siblings throughout Colorado participate in a 2 1/2 hour 
              interview that covers questions about personality, behavior, intelligence 
              and various mood and conduct disorders. Participants that meet certain 
              criteria are then contacted for a more extensive follow up interview.
            Executive Cognitive Function (ECF) - Two twin studies at IBG are exploring the role of Executive Cognitive Functions as they relate to human development and behavior. The ECF - LTS utilizes the LTS sample to investigate the functions of shifting, updating, and inhibiting. The ECF - CTS utilizes the Community Twin Sample and is designed to investigate the realtionship between ECF components and the development of behavioral disorders. 
            Colorado 
              Adolescent Twin Survey (CATS) In this study, twins fill 
              out questionnaires on a range of topics including information about 
              their personality, history of substance use, and demographics. These 
              twins are contacted through the Colorado Twin Registry, which is developed 
              with assistance from the Colorado Departments of Health and Education. 
              This study began in 1997, and thus far over 1000 families have participated. 
              The youngest respondents are 12 years old whereas the oldest twin 
            pairs are in their 60's. 
          
            Longitudinal 
              Study of Early Reading Development (LSERD) This study, 
              a collaborative effort with the University of New England in Australia 
              and Stavanger University in Norway, is designed to study genetic and 
              environmental influences on early reading and attention development. 
              Identical and Fraternal twins are being tested in preschool for pre-reading 
              skills, and after kindergarten, first grade, and second grade for 
              the development of early reading, spelling, and related cognitive 
              skills. Enrollment 
              is ongoing for same sex twins south of Fort Collins and north of Colorado 
            Springs.
            Colorado Longitudinal Disabilities Research Center          
              
            Since its inception in 1982, the 
              CLDRC has worked with over 1400 twin pairs to assess and find factors 
              that contribute to the development of various reading disabilities. 
              This testing is conducted over 2 days with twin participants contacted 
              throughout school districts in Colorado. Recruitment for this project 
              is ongoing.
            Longitudinal 
              Twin Study of Reading Disability (LTSRD) This new study 
              is a 5-6 year follow up with 12-25 year-old twins who participated 
              in the CLDRC. It is the first time a longitudinal study has been conducted 
              with twins who have reading disorders. The initial study calls for 
              an abbreviated battery that assesses cognitive, behavioral and reading 
              abilities and will enroll 200 twin pairs and 50 of their siblings.