http://www.youtube.com/watch?v=BkKWApOAG2g

This is fascinating. They share the same legs and circulatory system but have two hearts (and heads obviously), each controls one of the two arms and they can control their body quite literally together. They can drive for example.

It's weird to see two otherwise healthy and normal teenagers basically sharing an upper body. And their use of "we" and "I". Luckily in English addressing them is fairly unambiguous ("you" working both for 2nd person singular and plural).

Their situation makes for very serious implications though...for one, one of the girls will always know everything her sis tells her best friend or a boy or whatever...or imagine being in a conversation with them. Do you talk to one, or both? The other one is always 'there' if you don't.

Not to mention boyfriends and sex and masturbation and all these rather private issues. And like the guy at the end suggests: how will they function in a workplace? Will they earn as one person or as two? After all they only have two arms and two legs like you and me.

Very interesting.