> IMO there are other reasons as well.
> For instance qualia are insane delusions
> representing sensor inputs and other brain states,
> such as "feelings". We literally have "visions".

> Many more.
> ---------------------------------------------------
>
> http://www.foxnews.com/story/0,2933,410721,00.html
>
> Why We Are All Insane
> Tuesday, August 26, 2008
>
> By Robin Nixon
>
> Natural selection wants us to be crazy — at least a little bit. While true
> debilitating insanity is not nature's intention, many mental health issues may
> be byproducts of the over-functional human brain, some researchers claim.
>
> As humans improved their gathering, hunting and cooking techniques, population
> size increased and resources became more limited (in part because we hunted or
> ate some species to extinction). As a result, not everyone could get enough to
> eat. Cooperative relationships were critical to ensuring access to food, whether
> through farming or more strategic hunting, and those with blunt social skills
> were unlikely to survive, explained David C. Geary, author of "The Origin of
> Mind" (APA, 2004), and a researcher at the University of Missouri.
>
> And thus, a diversity of new mental abilities, and disabilities, unfurled.
>
> The nature of joy
>
> It might seem as though modern man should have evolved to be happy and
> harmonious. But nature cares about genes, not joy, Geary said.
>
> Mental illnesses hinder one in every four adults in America every year,
> according to the National Institute of Mental Health. And this doesn’t count
> those of us with more moderate mood swings.
>
> To explain our susceptibility to poor mental health, Randolph Nesse in "The
> Handbook of Evolutionary Psychology" (Wiley, 2005) compares the human brain with
> race horses: Just as horse breeding has selected for long thin legs that
> increase speed but are prone to fracture, cognitive advances also increase
> fitness — to a point.
>
> Let's take common mental conditions one-by-one.
>
> People with aggressive and narcissistic personalities are the easiest to
> understand evolutionarily; they look out for number one. But even if 16 million
> men today can trace their genes to Genghis Khan (nature's definition of
> uber-success can be measured by his prolific paternity), very few potential
> despots achieve such heights. Perhaps to check selfish urges, in favor of more
> probable means to biological success, social lubricants such as empathy, guilt
> and mild anxiety arose.
>
> For example, the first of our ancestors to empathize and read facial expressions
> had a striking advantage. They could confirm their own social status and
> convince others to share food and shelter. But too much emotional acuity — when
> individuals overanalyze every grimace — can cause a motivational nervousness
> about one's social value to morph into a relentless handicapping anxiety.
>
> Pondering the future
>
> Another cognitive innovation made it possible to compare potential futures.
> While other animals focus on the present, only humans, said Geary, "sit and
> worry about what will happen three years from now if I do that or this." Our
> ability to think things over, and over, can be counterproductive and lead to
> obsessive tendencies.
>
> Certain types of depression, however, Geary continued, may be advantageous. The
> lethargy and disrupted mental state can help us disengage from unattainable
> goals — whether it is an unrequited love or an exalted social position.
> Evolution likely favored individuals who pause and reassess ambitions, instead
> of wasting energy being blindly optimistic.
>
> Natural selection also likely held the door open for disorders such as attention
> deficit. Quickly abandoning a low stimulus situation was more helpful for male
> hunters than female gatherers, writes Nesse, which may explain why boys are five
> times more likely than girls to be hyperactive.
>
> Similarly, in its mildest form, bipolar disorder can increase productivity and
> creativity. Bipolar individuals (and their relatives) also often have more sex
> than average people, Geary noted.
>
> Sex, and survival of one's kids, is the whole point — as far as nature is
> concerned. Sometimes unpleasant mental states lead to greater reproductive
> success, said Geary, "so these genes stay in the gene pool."
>
> --
> Frederick Martin McNeill
> Poway, California, United States of America
> mmcne...@fuzzysys.com
> ******************************************
> "I never cease being dumbfounded by the unbelievable things people believe."
> - Leo Rosten
> ******************************************