How Our Predisposition Toward Empathy Taints Our Logic

Our sexually selected instincts for displaying sympathy tend to affect our belief systems, not just our charity and courtship behavior. When individuals espouse ideological positions, we typically interpret their beliefs as signs of good or bad moral character. Individuals feel social pressure to adopt the beliefs that are conventionally accepted as indicating a "good heart," even when those beliefs are not rational. We may even find ourselves saying, "His ideas may be right, but his heart is...

 Complex Brains as an Advertisement for Genetic Fitness

The healthy brain theory suggests that our brains are different from those of other apes not because extrava- gantly large brains helped us to survive or to raise offspring, but because such brains are simply better advertisements of how good our genes are. The more complicated the brain, the easier it is to mess up. The human brain's great complexity makes it vulnerable to impairment through mutations, and its great size makes it physiologically costly. By producing behaviors such as languag...