This. What this study shows is that babies can identify helpful and unhelpful people. They prefer the company of the helpful people. But this is really saying that babies can evaluate utility not morality.

Do your own research:

"Whoever mutilates, cuts, disfigures, perforates, unites or cements together, or does any other thing to any bank bill, draft, note, or other evidence of debt issued by any national banking association, Federal Reserve Bank, or Federal Reserve System, with intent to render such item(s) unfit to be reissued, shall be fined under this title or imprisoned not more than six months, or both." - Title 18, Section 333 of the United States Code

Nothing in there about passing back into circulation. However these people might not have the necessary criminal intent.

This sounds great, but unfortunately doesn't work.

The politician's staff can deliberately conceal the nature and degree of their impairment. This is especially the case in so-called safe seats in single party districts. The politician runs unopposed and the staff keeps their jobs. My coworker called up his state representative who had been in office longer than I've been alive. He was shocked when the rep actually answered the phone. He was even more shocked by the fact that the rep was exhibiting significant dementia. Halfway into the call, a staff member shooed the rep off the phone, apologized, and tried to whitewash everything.

For that matter I've heard several clinical psychologists express the opinion that psychopaths/sociopaths often have exactly the sort of personality traits that make good politicians or executives. They are charismatic, good an manipulation, and excel at social networking.

Not that I think there is necessarily anything wrong with someone who is mentally disabled holding office. It just depends on the disability. The term mental disability could reflect anything from dementia to dyslexia.

Actually he would probably say "Wear a kilt? Why? Is someone getting married?"