My fundamental belief in the inheritability of psychological traits, preferences, attitudes, and spirituality gave me the confidence to believe that I would be comfortably matched physically, socially and psychologically with my biological parents and siblings, if I chose to find them.
Twin studies have been highly valuable for estimating the inheritability of certain traits, including academic ability, personality, and interests; family and social relationships; mental and physical health; and physiological measurements. Researchers have been particularly interested in the prevalence of psychopathology, substance abuse, divorce, leadership, and other traits and behaviors related to mental and physical health, relationships, and spirituality. Research suggests that genetics play a strong role in the development of personal characteristics by serving as a blueprint for physical, social, and emotional development. Twins separated at birth and reared in different families have an equal chance of being similar to the co-twin in terms of personality, interests, and attitudes as one who has been reared with his or her co-twin. Researchers have produced surprising results showing that social attitudes, behavior, and dental health all have a genetic influence.
Consensus amongst the scientific world is that behavior can be explained by a combination of both nature (genetics) and nurture (environment). This leads to the conclusion that similarities between twins are due to genetics and the differences between twins reared apart are due to the environment. Heredity is an important determining factor in shaping physical appearance, mental acuteness, preferences, personal characteristics, and personality. Researchers have uncovered remarkable similarities between twins raised in separate homes with different parents to be remarkably strong. Examination and scrutiny gives significant weight to the importance of genetics as a key factor in determining physical appearance and attributes, as well as personalities and inherent abilities. The inheritability of academic ability, personality and interests, family and social relationships, mental and physical health, and other physiological measurements has inferred correlations for children raised outside their genealogical, biological, and ancestral groupings, but psychologists are not satisfied to rest on that conclusion alone.
Questions still remain regarding to what degree certain behavioral traits can be explained by genetics and the environment. Many studies have been conducted to understand how siblings interact and influence one another, how family environment has an impact on the mental health of adolescents, and how adoptive families are similar to and different from biological families. Extensive research on environmental and biological influences on adopted children and children biologically related to the parents has allowed sibling and parental influences to also be incorporated into the research. The Minnesota Twin Family Study has provided scientists a clearer understanding of the role of genes and environment on human development. The landmark series of investigations have helped identify genetic and environmental influences on the development of psychological traits; findings that have received both praise and criticism. On multiple measures of personality and temperament, occupational and leisure-time interests, and social attitudes twins raised apart were found to be about as similar as those reared together. This evidence for the strong inheritability of many psychological traits should never detract from the value or importance of parenting, education, and other interventions.
Judith Land
Adoption Detective: Memoir of an Adopted Child 
I hope it’s okay for me to be honest. When I found my birth mother, I didn’t like her. She never wanted children and was embarrassed each time she got pregnant. I hate the fact that I am anything like her. Growing up I only knew that she was 21 and did not keep me. I made it a point to make sure I went to college and did not get pregnant young and make the mistakes she did. I don’t know her well enough to know her likes and dislikes. She never would let me into her personal life. I only know that she has not gone to college or from what I see has done anything except hide out. I feel that I do have her introverted nature, but I am a go getter. I will write a book. I will tell my story. I will get on a place and go to a foreign country without thinking twice if I had the money lol. She is not like me in the way at all. I still wonder where I get those things from. My adoptive parents don’t seem to be as adventurous either.
Throughout the millennium our ancestors survived natural disasters, war and pestilence disease and hardships of many kinds. We are here today because our parents, grandparents and those who came before us were more cunning, cooperative, brutal or intelligent than others, or maybe just plain lucky or better at hiding. Whatever the reasons for survival are, we can be assured of the choices they made, the paths they chose and the bridges they crossed. Survival is a pretty big reason to be proud and celebrate the lives of our antecedents, othewise we won’t even exist.
Individuals separated from family who find their way in the world on their own are often admired in books and movies. I hope you do follow through with your idea to write a book and share your story with the world. Children separated from their parents that thrive and follow a moral path have a universal appeal to people of all ages in every culture around the world.
We become who we are based on our self-image. Our self-image sets the boundaries of individual accomplishment and determines what we become. Self-esteem is the single most important emotional gauge of future happiness, success, feelings of well being, confidence and positive assurances. To create a positive future it is necessary for all of us to consciously modify the personality, human behavior and the outcome. I wish you Godspeed and good fortune.
wow what a fascinating study.then we should see how murder affects families and maiming and hey let’s randomly lockup families and hmmm what other sadistic horrors could we do to families to study morons mill stones for every one]
You always speak the truth. You are wise. Those who are subjected to physical and emotional abuse during childhood tend to acquire antisocial personality disorders that usually cause them to act out in more severe ways. This is likely how messed up we humans can become without any hints of genetic predisposition.
As an adoptee, I always found these twin studies and the science of epigenetics fascinating. Thank you for writing about it! BTW…I tried to follow your blog, but the link on your home page doesn’t seem to work. Just thought I’d let you know 🙂
Thanks for the feedback, I hope the problem has been corrected.
https://www.adoptiondetectivejudithland.com (Website)
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https://www.amazon.com/Judith-Land/e/B005BT0U4G%3Fref=dbs_a_mng_rwt_scns_share
I met my birth mother at 19 years old (and father – they got married a year after they gave me up, long story). I was shocked by how much I moved and sounded like her. We have similar interests and I am so much more like her than my adoptive mom. I was always on the side of nurture over nature until I met her. I also recognize some traits from my biological father but with my bio-mom, it was uncanny.
Thanks for sharing. I’m happy for you. It’s true that nurture is most obvious until about age 18 and then we slowly evolve into being more like our roots. The Minnesota Twin studies offer amazing scientific proof of inheritable characteristics that shape our being.
I had some similar experiences that were positively haunting and alluring and beyond coincidence. Scientists claim that nurture is dominant through the teen years but into our twenties and beyond nature tends to expose our true being and unique human characteristics, based on inherited traits that helped our ancestors survive over the millennium…