Societies would _not_ be better off if everyone were like Mr Spock, all rationality and no emotion. Instead, a balance - a teaming up of the internal rivals - is optimal for brains. ... Some balance of the emotional and rational systems is needed, and that balance may already be optimized by natural selection in human brains.
David EaglemanThe continuous networks of neural circuitry accomplish their functions using multiple, independently discovered strategies. The brain lends itself well to the complexity of the world, but poorly to clear-cut cartography.
David EaglemanOdor carries a great deal of information, including information about a potential mate's age, sex, fertility, identity, emotions, and health.
David Eagleman