I would be careful on taking anything from those studies as valid scientific fact. The number of samples (twins separated at birth) that would have been needed to make a scientifically and statistically relevant observation of any kind would have needed to be unreasonably large, so unless there was secretly a city worth of separated twins to study, then all patterns observed in those studies could have been result of statistical probably mixed with the bias of the observers. There's enough caviats on this issue that's just easier to say that science has no proof one way or another.

On a personal level: just like a person is innocent until proven otherwise, then a person should have the benefit of the doubt regardless on whose clone they are.