text: How about if you come up with a word-association test, where you ask them to say the first word that comes to mind when you say another word.  Do about 10 words, and test the twins separately (of course).  Then compare their tests and see if they said the same words (for example, if your word was "cold" and they both said "ice cubes" that could help you prove that twins are on the same wavelength or something.)  Also, instead of doing your project on twins in general, why don't you try to narrow down your research field, like maybe just do your project on identical twins or just fraternal twins, or whether twins think alike or whether they can sense the other twin's feelings, or something like that.  There are plenty of research books on the subject in the llibrary, and the Internet is always a great resource too.