Imagine seeing someone who looks exactly like you walking down the sidewalk opposite you. He/she looks so much alike that you are convinced he/she could be your twin. It turns out, he/she is. If there is one thing that will stand out for me from this semester, it will be some of the discussion we had on twin studies. 
The study I described is a psychological study that separates twins at birth and reunites them decades later. It is discussing the age old debate of Nature vs Nurture. Does our genetic makeup or the environment in which we are raised determine our personality and intelligence. According to this study, the Monozygotic twins, share 100% same genes, who were separated show some similarities through the separation and some dissimilarities. Lets take the story of Oskar and Jack regarding personality. They were raised in separate regions of the world and still ended up with similar personality scores on tests: intense, loyal, and politically engaged. However, they both supported groups who were polar opposites. Oskar supported the Nazi movement, Jack was helping to build the Jewish state of Israel. The fact that their personality traits were very similar shows that the genetics approach is at least partially true. Moving on to intelligence. When studies of separated Monozygotic Twins are examined, we find similarly that MZ twins have very similar scores on intelligence tests. The fact that these two groups both show a very similar personality and intelligence suggests again that genetics is a key part of the picture of human characteristic. However, if this was the case why would the twins not be perfectly aligned? There is still variablity within these studies proving that environment also has a role. We should all be aware of these interesting studies because, who knows, you could be walking down the street and could miss your twin on the other sidewalk. For more on twin studies and what Harvard is doing with them click here
