Conjoined Twins

Limited search capability here at work, and I’ll forget by the time I get home.

Drinking: one twin is an alcoholic, the other not (Chang and Eng)–do both end up getting drunk when only one drinks?

Thinking: joined at the head with a union including some brain, to what extent can thoughts be shared? And if they can be, how do they know who’s thought it was originally?

If one twin commits a capital crime, and they can’t be seperated without killing them both, how would death penalty, or even long-term incarceration be applied? Is the other twin simply an accomplice?

I recall seeing the subject of imprisonment discussed on the BBC quiz show Q.I., the presenter told the story of conjoined twins who were involved in a fight (or rather, one of them was). The judge in the case ruled that he would ordinarily sent the criminal to jail for the crime but it would constitute wrongful imprisonment of the innocent twin so he had no choice but to reduce the punishment to a fine.

Sorry I don’t have a cite, just my own recollection of the story.

I also remember reading a similar thread on these forums (in fact I think I may have started one) where the consensus seemed to be that imprisoning an innocent man is a greater affront to justice than letting a guilty man walk free. There is still the issue of whether the ‘innocent’ twin would be considered an accomplice or a bystander. If the twin were considered to be an accomplice then he may also face jail, which simplifies things somewhat but the accomplice would have a shorter sentence so the problem would only be delayed until release day. Being an accomplice to a crime and failing to prevent one are different ball parks and it would be a minefield to determine just how active the ‘innocent’ twin was in the crime.

Let’s just hope it never happens.

Drinking: this depends on whether or not there is a significant blood flow between the twins. Some share only minor vessels and capillaries, so the alcohol seepage between the two would be pretty minimal. Some share major arteries, so the blood supply crosses from one to the other willy-nilly, and they would both get drunk at the same time. AFAIK, Chang and Eng had a sort of “moderately” shared bloodflow. The one who survived the other (I think Chang survived Eng?) eventually died because blood flowing out of himself wasn’t being returned by his brother–but it took hours.

Thinking: cognition is simply too complicated for this question to be answered satisfactorily; the twins would have to share significant portions of the cortex for them to “think” the same things. Many twins do have areas of shared sensation, though.