Brains are built by genes. Those brains that reflect the optimisation target of the genes are the ones that will become ancestors. So it is reasonable—on grounds of basic evolutionary biology—to expect that human brains will generate behaviour resulting in the production of babies—thus reflecting the target of the optimisation process that constructed them.
In point of fact, human brains /do/ seem to be pretty good at making babies. The vast majority of their actions can be explained on these grounds.
That is not to say that people will necessarily consciously seek to maximize their expected fitness. People lie to themselves about their motives all the time—partly in order to convincingly mislead others. Consciousness is more like the PR department than the head office.
Of course, not all human brains are maximizing their expected fitness very well. I’m not claiming that nuns and preists are necessarily maximizing their expected fitness. The plasticity of brains is useful—but it means that they can get infected by memes, who may not have their owner’s best interests at heart. Such infected minds sometimes serve the replication of their memes—rather than their onwner’s genes. Such individuals may well have a complex terminal value, composed of many parts. However, those are individuals who—from the point of view of their genes—have had their primary utility function hijacked—and thus are malfunctioning or broken.
Brains are built by genes. Those brains that reflect the optimisation target of the genes are the ones that will become ancestors. So it is reasonable—on grounds of basic evolutionary biology—to expect that human brains will generate behaviour resulting in the production of babies—thus reflecting the target of the optimisation process that constructed them.
In point of fact, human brains /do/ seem to be pretty good at making babies. The vast majority of their actions can be explained on these grounds.
That is not to say that people will necessarily consciously seek to maximize their expected fitness. People lie to themselves about their motives all the time—partly in order to convincingly mislead others. Consciousness is more like the PR department than the head office.
Of course, not all human brains are maximizing their expected fitness very well. I’m not claiming that nuns and preists are necessarily maximizing their expected fitness. The plasticity of brains is useful—but it means that they can get infected by memes, who may not have their owner’s best interests at heart. Such infected minds sometimes serve the replication of their memes—rather than their onwner’s genes. Such individuals may well have a complex terminal value, composed of many parts. However, those are individuals who—from the point of view of their genes—have had their primary utility function hijacked—and thus are malfunctioning or broken.