Researchers at Jerusalem’s Hebrew University studied 1,657 families of twins born in 2004/5. In 63 cases, one of the twins had a development delay or disability. The other twin was found to have a higher cognitive empathy than those with a normal twin.

https://www.jpost.com/health-and-wellness/article-698420

https://srcd.onlinelibrary.wiley.com/doi/10.1111/cdev.13740