Subtle genetic tweaks in your taste receptors help to determine whether you prefer drinking coffee or tea. Genetics also play a role when it comes to our inclinations or aversions for all sorts of different activities. Instead, as Stefánsson found with crosswords, it seems our genes influence our natural inclinations towards doing certain activities. The latter points to where genetics might wield its weightiest influence over our life paths - our personality traits. "This reflects the fact that our genes influence the ways our brains form, which impacts how we think and interact with the world," says Dick.