A debate of nature vs. nurture, as in whether it is our inherited genes or environmental factors that affect our behavior, has been going on for years. There are no true experiments on genetic inheritance influencing behavior due to ethical reasons. Only quasi-experiments and theories of pre-existing data are available that are on genetics or environmental factors affecting behavior. With the few studies existing one can still argue that genetic inheritance is a major aspect in what affects behavior but environmental factors can be more affective.
There are two main theories of human behavior. Some scientists and psychologists believe in the “nature” theory, that one behaves as they do because of their inherited genetics. Others believe in the “nurture” theory where one behaves in certain ways because they were taught to. Researches behind these theories involve studying monozygotic (MZ) twins and dizygotic twins (DZ) raised together or apart (MZA/DZA). There are only quasi-experiments and research on the differences between MZ, DZ, MZA, and DZA twins’ behavior. Consequently there are so many other factor influences and bidirectionality that should be considered when looking at these studies.
A person’s genes can affect their happiness to a certain extent. Lykken says, “It may be that trying to be happier is as futile as trying to be taller and therefore is counterproductive”. He had carried out a quasi-experiment in 1996 where he got MZ, DZ, MZA, and DZA twins to answer a questionnaire. The questionnaire was designed to measure Subjective Well-being (SWB) and the results were grouped. The correlation in the SWB scores between the MZ twins was 0.44 and 0.52 between MZA twins. The correlation between DZ twins was close to zero and similarly for DZA twins as well. In all, the correlation was less than 0.05 between happiness and educational levels, income, social status, marital status, and