I think this is much the same as the arguement that intelligence is a natural and inevidible development of tool use. The difference is that this assumes that females would be able to recognize something that we are still having trouble defining, intellegence. The fact is that females usually choose the mate that looks the healthiest. In stable situations intelligents and curiosity often can distract the indvidual from basic survival and hurt their chance of passing on their genes. In times of trouble intelligents can provide the abillity to adapt to a difficult situation quickly. Human intelligents is just a demonstration of how tough life has been over the generation.