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.
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.
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
is ongoing for same sex twins south of Fort Collins and north of Colorado
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
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.