It is general knowledge now that our genes determine such physical traits as eye color, hair colour, the shape of your nose, height and so on. But when it comes to more abstract attributes like intelligence, extroversion vs introversion, and sexuality, the question of the influence of environmental factors also comes into play.
To what extent does our environment influence behaviour? Are we born this way or subject to our life experiences? Would you behave differently if you were 10 cm taller? Can you really choose who you want to be?