[mtgex]

I'm not sure, the article doesn't mention any of that.

It actually tries (weakly) to claim the opposite, with statements like "Carlos and Wilber both had very similar white mobile phones" and "We are a little bit more ego-centric, bigger flirts."

Nothing about nurture playing a role though.

[DoreenMichele]

It's the first article I could find that referenced the twins in question. But researchers said they were surprised how much impact upbringing had. Unlike a lot of twins separated at birth, these were raised in very different socioeconomic circumstances.

Project about them: http://drnancysegaltwins.org/bogota-twins-project-gallery

The best reference I can currently come up with is this comment by tokenadult who has a longstanding interest in twin studies:

https://news.ycombinator.com/item?id=10100109#10100644