Whether or not your twin or child provided a sample, we still consider your DNA sample extremely valuable. This study compares your DNA sample to your psychological data (obtained during your interview and/or lab), so no comparison between twins or other family members is necessary. However, we would like as many participants as possible to partake in this great opportunity, so we really appreciate it when all family members are able to participate.

If a participant has already given a DNA sample, we are asking that they please consider giving another one to this project. Our earlier samples were obtained at a time when DNA extraction technology (e.g. separating the DNA from the other parts of the blood) was brand new and blood was tested for only a very limited number of genes. The technology in this area has grown by leaps and bounds in the last few years, making it possible to assess thousands of different genes. In order to take advantage of this huge improvement, we need another blood sample. The National Institutes of Health (NIH) collaborates with the MCTFR on this project, providing us with the use of their sophisticated equipment to process our DNA samples. The NIH also keeps a portion of the DNA sample for their research, which is important because the NIH has a much larger pool of participants from across the country. Adding samples from our participants to the NIH’s pool will enable researchers to advance the understanding of human behavior even further. Click here to learn more about how we safeguard your privacy during this process.

No, unfortunately that is not possible. First, to protect your confidentiality, your samples are de-identified through use of a meaningless ID code that is used to identify samples. This important privacy measure makes it impossible to provide individual results by matching samples with findings. Secondly, our Humans Subjects Committee forbids us from providing such feedback, in part because we can’t know ahead of time what we will find, what significance it will have, or how people will deal with it.

Basically, the blood cells containing DNA are separated from those that don’t, frozen indefinitely, and not used for anything right away. As scientists discover genes that potentially influence behavior, we will be able to extract small samples of DNA from the storage repository, analyze them, and relate them to our behavioral data.

The samples are shipped directly to Rutgers University in New Jersey, where DNA is extracted (extraction involves the separation of DNA from the other parts of the blood sample). A portion of the extracted DNA is then saved at NIH for their research, and another portion is sent back to us for our research.

Genes are essentially instructions that your body uses to build proteins that carry out various functions in your body. Some proteins affect how the brain works. We are doing a psychological study, so we are interested in determining information related to the brain and behavior. For example, do genes produce proteins that influence how happy people tend to be or what their brain wave patterns look like? Are happy people more likely to have a gene that produces a certain type of transmitter (message sender) in the brain? Are impulsive people more likely to have certain genes than others, perhaps genes that control neurotransmission (message sending) in certain parts of their brains? These are the types of questions we hope to answer by studying your DNA.

In other words, the goal of this research is to identify genes that are related to psychological traits. For instance, if a gene that controls an inhibitory neurotransmitter is identified, we might check to see if impulsive people are less likely to have this gene. Confirming this hypothesis might help us understand why some people are more impulsive and likely to take risks.

As scientists discover genes that potentially influence behavior, we will be able to extract small samples of DNA from the storage repository, analyze them, and relate them to our behavioral data. It is important to realize that the human genome project has just begun to understand the role of specific genes and how they influence behavior. Over the next decade, we foresee significant scientific discoveries concerning how genes function and interact with the environment. We are honored and pleased to be collaborating in this effort and anticipate that it will assist our Twin Family Study as we continue to solve the mysteries of human behavior.

Hopefully, it will ultimately benefit society by allowing us to better understand human behavior.

Importantly, genes can only account for a small part of why people behave as they do, so we will never find a gene for a psychological attribute in the way that medical researchers find a gene that causes a disease. Any genes we find associated with a trait would probably have a relatively small influence on the trait’s expression. In other words, environmental factors still play an important role in how genes are expressed. One advantage of our research is that by understanding the effects of genes on behavior, we will have a much better chance of identifying important environmental factors. With that knowledge, we can understand how changing environmental factors may improve people’s lives, and we can give people better opportunities to understand how choices they make affect characteristics like their general level of happiness.