Project Talent Twins and Siblings Study
Our sibling relationships are likely to last longer than any other we have in our lifetime. They play an important role in our learning and development. Looking at differences between siblings helps us understand how nature and nurture affect how we age.
What is this study about?
If you were a Project Talent participant, you probably know that all students attending your high school in the spring of 1960 were part of the study. If your sibling was in school with you, then he or she is a member of Project Talent, too.
We would love to hear from you. If you would like to receive updates on Project Talent, please contact our team.
The Twins and Siblings study looked at differences in environments, experiences, and health between twins and their siblings. Since identical twins share the same set of genes, any behavior and health-related differences between identical twins are due to their environments, not genetics. Looking at how identical twins differ in behavioral traits and health outcomes over their lifetime can help us understand which ones are strongly influenced by the environment versus resulting from genetics.
Similarly, when fraternal twins or siblings of twins share behavioral traits or have the same health outcomes, we can look for genetic elements that are shared across family members. This helps us understand which traits and diseases are largely controlled by genetics.
Why does this matter?
Knowing how our genes and our environment affect our education, careers, and health can help researchers in several ways. For example, it can help scientists develop treatments for different diseases. It can also help patients and their doctors make better choices about treatments that work best for them. Learning how our sibling relationships affect our mental health and well-being in adulthood can help shape interventions designed to protect against loneliness and depression.
What did we do?
We contacted 2,300 pairs of twins and 520 of their siblings to ask them to take part in a survey. The survey included questions about their families, education, careers, and health. We also asked questions about twins who are the same sex, such as how similar they are physically (eye color, hair, height, and weight), how often they were mistaken for one another, and whether they knew if they were identical or fraternal twins. Over 50 percent of twins responded to the survey, along with 46 percent of their siblings.
What did we learn?
If you are a researcher looking for Project Talent data, please visit our For Researchers page.
We learned that genetics influence the amount of education we complete. This is because our genes influence both our ability to learn and our personality, and these two traits affect the level of education we pursue. However, the extent of this influence varies between men and women, and across social and economic conditions. For men, educational achievement is influenced almost equally by genetics and household economic status. But among women from middle to low household economic status, economic conditions exert greater influence on education than genetics. Women from less advantaged households may be more likely to stop their education early compared with men from the same environments.
What's next?
This study helped us understand how our genetics and our family environment affect our behaviors—which, in turn, impact our health. Next, we want to learn how educational achievement and health outcomes between families who grew up in the same community are the same or different.
