Designers can well design things more complicated than they are.
Agreed. Also, there is a continuum from pure evolution (with no foresight at all) to evaluation of potential designs with varying degrees of sophistication before fabricating them. (I know that I'm recalling this from a post somewhere on this site - please excuse the absence of proper credit assignment.) An example of a dumb process which is marginally smarter than evolution is to take mutation plus recombination and then do a simple gradient search to the nearest local optimum before evaluating the design.
Also, there is a continuum from pure evolution (with no foresight at all) to evaluation of potential designs with varying degrees of sophistication before fabricating them.
I'll add that evolution with DNA and sexual reproduction already in place fits on a different part of this continuum from evolution of the simplest replicators.
[...] SIAI's Scary Idea goes way beyond the mere statement that there are risks as well as benefits associated with advanced AGI, and that AGI is a potential existential risk.
[...] Although an intense interest in rationalism is one of the hallmarks of the SIAI community, still I have not yet seen a clear logical argument for the Scary Idea laid out anywhere. (If I'm wrong, please send me the link, and I'll revise this post accordingly. Be aware that I've already at least skimmed everything Eliezer Yudkowsky has written on related topics.)
So if one wants a clear argument for the Scary Idea, one basically has to construct it oneself.
[...] If you put the above points all together, you come up with a heuristic argument for the Scary Idea. Roughly, the argument goes something like: If someone builds an advanced AGI without a provably Friendly architecture, probably it will have a hard takeoff, and then probably this will lead to a superhuman AGI system with an architecture drawn from the vast majority of mind-architectures that are not sufficiently harmonious with the complex, fragile human value system to make humans happy and keep humans around.
The line of argument makes sense, if you accept the premises.
But, I don't.
Ben Goertzel: The Singularity Institute's Scary Idea (and Why I Don't Buy It), October 29 2010. Thanks to XiXiDu for the pointer.